I’ve been off TV for five or six months, working diligently day and night at my new educational center in east-central Missouri, The Evergreen Institute, where I teach classes on solar electricity, wind energy, green building, natural building and more. 

So, when I moved back to Colorado for the winter and had a few minutes of free time at night, I started to watch a little TV.

One of the first things I noticed was that the bulk of the car ads are extolling the virtues of big gas guzzlers, SUVs and big trucks. I’m hoping it is Detroit simply trying to dump their unsold gas guzzlers, but I fear it is their effort to persuade us — once again — that bigger is better.

Another thing I’ve noticed is that those ads featuring high mileage vehicles often “brag” about cars that get a whopping 24 to 30 miles per gallon.

I have two things to say about this situation. First, have we no memory at all? Have we all forgotten the economic kick in the pants that $4 per gallon gas delivered?

Let’s remember: As the global economy recovers, chances are gas consumption will rise, dramatically, backsliding us into the ugly, painful days of $4 a gallon gas. This, in turn, could stimulate another economic downturn.

Let’s use our brains for once. Don’t let anyone tell you that a car that gets 30 miles per gallon is fuel efficient.  Fuel efficient cars get 40 and 50 miles per gallon, even more. That’s the target we should be shooting for, and fast!  Let’s insist on it.

How long has it been since you last checked the real-world gas mileage of your car? Have you ever done it?

It can be all too easy to assume your car gets 30-something mpg — or whatever the sticker said when you bought the car — and never realize that its actual gas mileage has declined over the years and now is far off what you expect. But it's important to keep tabs on your car or truck's mpg.

First and foremost, "knowing is half the battle," as they used to say in the old G.I. Joe cartoon PSAs from my childhood. In other words, the first step to increasing your car's gas mileage (and saving money) is to know what it actually gets. Also, unless you're lucky enough to have a real-time mpg display in your car, there's no better way to better understand how driving habits influence gas mileage than to check the numbers. As in, on this tank I ran the air conditioning more than usual (you would see the mpg decline), or on this tank I drove the speed limit to work rather than speeding to make up lost time (you would see improved mpg). Last but not least, regularly checking your vehicle's mpg can spot maintenance issues before they become leave-you-stranded and wicked-expensive problems.

If you're a gas mileage geek like me, you'll calculate your car's mpg after every fill up. But even just checking mpg once a month or so will give you real numbers that will make it easy to adjust your driving habits so you save gas and money. Think of it as a personal challenge and you'll find it easier to get excited about the math — can you beat last month's personal best of 36 mpg? Can you beat the official EPA fuel economy estimate for your car?

And, to top it all off, you'll probably be surprised how easy it is to calculate gas mileage. Even a mathematically disinclined journalist like myself can do it. All it takes are two numbers and simple division. How to Calculate Gas Mileage will walk you through the steps.

For what it's worth, here's my system. I write down the number of miles on my trip meter on the credit card receipt from the gas station, which lists the number of gallons I bought. I also write down the car's overall mileage, just to help me track the car's mpg over time. I then plug all those numbers into a super-simple Excel spreadsheet, which does the simple division for me and automatically fills in the mpg for each tank. I can then track the car's mpg over time and see how it changes with the seasons, my driving habits, as I put off maintenance, after I got new tires, etc.

So, do you ever check your gas mileage? If so, how do you do it? If not, why not? Share your two cents by posting a comment below.

The Car Allowance Rebate System, formerly known as the Cash-for-Clunkers bill, takes effect today, July 1.

Yesterday, President Barack Obama signed the bill into law that pays consumers up to $4,500 in credit for trading in their cars or trucks for more fuel-efficient vehicles. The $1 billion program is overseen by The National Highway Traffic Safety Administration.

Details of how the plan will be rolled out are still being discussed. The full release is expected by July 24, but cars purchased between July 1 and Nov. 1, 2009 (if the funds do not run out before that) will qualify.

Here are some requirements listed from the CARS program website:

• Your vehicle must be less than 25 years old on the trade-in date.
• Only purchases or leases of new vehicles qualify.
• Generally, the vehicles you trade in must get 18 or fewer miles per gallon. You can check your current car's gas mileage estimate here.
• The new car being purchased must get a minimum of 22 miles per gallon and cannot exceed a price of $45,000.
• The vehicle you trade in must be drivable.
• Trade-in vehicles must be registered and insured continuously for the full year preceding the trade-in.
• The vehicle that you are trading in is required to be destroyed. Therefore, the value negotiated with the dealer for your trade-in is not likely to exceed its scrap value.

The CARS rebate does not count on top of the trade-in value of your vehicle. When you trade your car in, you do not need to do any paperwork with the government because the dealer will apply the credit when you buy the new vehicle.

The bill is designed for people with older, inefficient cars who are looking for new, more fuel-efficient cars. But there have been criticisms that the purpose of the bill is more for stimulating car sales than greening America’s fleet, since the gas mileage standard is just a 4 mpg increase.

Others, such as the Washington Post, are criticizing the bill for not providing enough money. The $1 billion of credits is only expected to increase car sales by 250,000 cars. Businessweek quoted Jeremy Anwyl, chief executive of Edmunds, saying that the program will not help the auto industry because auto sales would need to increase by 3 million vehicles more to get them out of the bad situation they are in now. But most automakers and auto dealers support the program.

What do you think about the new program? If you qualify, what kind of car would you get? If you don’t qualify, what kind of car would you want to get? Share your thoughts by posting a comment below.

Man, I sure hope I don't get kicked out of PETA for this.

I'm replacing MAX's aluminum windshield frame with something more substantial — a steel tube the same size as the roll bar. It will support the roof (coming soon) and provide a smidgen of side impact protection (more of that coming soon, too).

The trouble is that I live in deer country, on Eight Dollar Mountain in rural southern Oregon. It's bear country, too. I've seen bear in the Kinetic Vehicles driveway and our secretary, Jacky, shooed one away from her trash cans last winter, “Bad bear! Scat!” I suspect the bear ran away out of fear that Jacky was rabid.

It's even cougar country — my friend Dave, who has appeared in this blog a couple times, dang near tripped over one in his mud room this April.

But mostly it's deer country. Seeing a deer here is no more surprising than seeing a cow in Wisconsin.

I find deer charming. Every time I drive to my cabin and find them frisking about, converting my garden to venison, I can't resist calling to them, “I'm home, deer!”

Besides, they help the economy. I have a friend who is saving for his daughter's college tuition thanks to public interaction with deer: He drives a tow truck.

I hit a deer with a motorcycle once. We were both trying to dodge and we outsmarted each other. Although neither of us was killed, neither of us particularly enjoyed the experience. If I'd been driving MAX, the deer would’ve come over the hood and right into the cockpit with me, which wouldn't have improved either of our moods.

So MAX is getting what I call an auxiliary roll bar. But if local accident statistics are any guide, deer strikes are a lot more common than rollovers. I'm not sure how to discuss this in the brochure …

How's this? “The Kinetic Vehicles auxiliary roll bar helps keep wildlife in its natural environment.”

Photo by Jack McCornack

Browse previous MAX Updates.

Read the introductory MAX article, Here Comes the 100-mpg Car.

Visit the Kinetic Vehicles website for more technical details on MAX.

Don't pay the ransom, I escaped! Wow, it's been a busy month for me, and I apologize for the lack of updates recently.

The last weekend in May was MAX's farewell public showing in its Escape from Berkeley trim, at a fun, wonderful event called the Maker Faire.

We were there to show the flag and drum up business for Escape from Berkeley II. I figured if the Escape folks were willing to give us five grand for winning the event last year, the least we could do is encourage others to join in the fun this year. So we pulled off the streamlined body bits and put back the stylish-but-slow fenders and lights and all, and drove down to San Mateo, Calif., for one last hurrah.

Now we're back, and we have to knuckle down on the streamlining. In order to reach 100 mpg, we’ll have to get MAX down to the drag coefficient of a typical modern sports car.

The drag coefficient (aka “coefficient of drag”, abbreviated Cd) is a comparison of the drag of an object versus a flat plate of the same frontal area. A Mazda Miata, for example, has a Cd of 0.38.

MAX gets better mileage than a Miata because (among other things) MAX is so small it doesn't have a lot of frontal area. But MAX’s Cd is about 0.7, which is pretty terrible. That’s about the same drag coefficient as a shoe box.

Obviously, we have to make a lot of improvements, and one feature we can improve is a curved windshield. Hey, if you were making a windshield for a shoe box, it would look a lot like MAX's windshield does now — a flat panel right across the front of the cockpit.

But unfortunately a curved windshield will blow our $10,000 budget, because there's nothing off the shelf that will fit MAX (the windshield is only 33 inches wide — more than a foot narrower than the Miata windshield, for example) and custom-curved windshields cost a bundle.

So how about a split windshield, with a steep rake and a deep V to emulate a curved windshield? It'll be pretty cheap, and it would add to MAX's old-timey personality. I think I like it ... though I wasn't willing to commit the glass cutter before I saw how it looked.

Cardboard is a nice medium for conceptualizing design features, but it has its limitations. It should come with a sticker that reads, Warning: Remove Cardboard Before Operating This Vehicle. Nowhere would that be more important than the windshield …

Photo by Jack McCornack

Browse previous MAX Updates.

Read the introductory MAX article, Here Comes the 100-mpg Car.

Visit the Kinetic Vehicles website for more technical details on MAX.

The highly anticipated Chevrolet Volt is getting ever closer to the showroom floor. Whether you think of it as an electric car or a plug-in gasoline-electric hybrid, the Volt represents a significant step forward for mass-produced fuel-efficient cars. 

The Volt is different than other hybrids on the roads today in that it uses electricity as the sole means for powering the car; the gasoline engine works only to recharge the car’s lithium-ion battery pack. GM estimates that the Volt will travel up to 40 miles without using a single drop of gasoline, more than enough to cover the average American’s commute to work. Recharge your Volt while at work and you’d then be able to drive home without burning any gasoline. If recharged via a renewable energy source, the car’s power would be entirely emissions-free. 

You can learn more about the Volt in The Volt: An Electric Car That Could Change Everything and Update: The Chevy Volt, the Electric Car of the Future. 

Last week, GM vice chairman Bob Lutz appeared on The Late Show with David Letterman to talk about the Volt. Letterman recently purchased a Tesla Roadster, an all-electric car that gets more than 200 miles per charge, and previously said that the Volt’s 40-mile capability was “crap.” (You can watch Lutz and Letterman’s exchange below.) 

When asked why GM couldn’t make a car with performance comparable to the Tesla, Lutz replied that GM needs to sell cars at volume, and thus needs to give the Volt a practical price tag. Lutz then said that when the Volt hit dealerships in late 2010, it would cost about $40,000 (the Tesla sells for more than $100,000). 

But the first 200,000 Volts Chevrolet sells will be eligible for a federal tax credit of $7,500, bringing the final price to about $32,500. 

So, what do you think? Would you pay $32,500 to $40,000 on an electric vehicle such as the Volt? What if gas prices rise back up to $4 a gallon, or more? Share your thoughts by posting a comment below.

I've been on the road for a couple weeks, laptop by my side, weighing the suggestions about pumping up MAX's performance (see Update No. 26 and the numerous comments attached to it).

One that especially sparked my interest was the idea of relocating the turbocharger to the back of the car — the commenter explained the idea in detail and it makes sense. The comment, from Glen2Gs, ended with this:

“… The "Still Born" Top Gear USA television program took a VW Rabbit Diesel (AKA The Sipster) and were able to "tweek" it to 84mpg with a 0-60 time of 7 SECONDS!

http://www.topgear.com/us/features/more/project-sipster-sipster-indeed/  

May be time to send the Kubota ... packing.”

For those unfamiliar with the Sipster project, they took an '81 Volkswagen Rabbit and put in a power plant from an '03 Volkswagen Jetta TDI (diesel). The word “put” is a bit of an oversimplification and waaay out of my skill set, but that's the basic idea. They backed up the engine swap with aerodynamic modifications and got the results quoted above. It's a good story and worth the read, and it got new folks interested in the subject. All in all, I think it's pretty cool.

But before I toss the Kubota and trade MAX in for a Rabbit, we're not really talking apples and apples here. For example, they used different cardboard-and-duct-tape aerodynamic modifications for the performance runs and the economy runs. But the X Prize Foundation isn't going to let us change MAX’s body depending on which task we're facing, so that's apples and oranges at best.

Maybe not even apples and oranges, since they were “hypermiling” — drafting, coasting, and generally making life rough for the surrounding traffic— for their economy run. So we're comparing driving techniques as much as we're comparing cars, so maybe it's apples and donuts.

But still, 84 mpg is pretty spectacular. But then I read how they measured the mileage and said, “Whoa, that's how the hucksters did it back when they were selling high mileage refrigerator magnets to tie on your fuel line.”

In brief, one morning they filled the tank all the way up to the gas cap (diesel cap?), drove 70 miles, and filled it to the gas cap again. The pump stopped at 0.833 gallons, less than a gallon by a pint and a third. Pretty simple, so what could be wrong with that?

What's wrong is that as the day heats up, the fuel heats up expands, filling the tank from the inside. A factor in this case is the TDI system re-circulates fuel through the fuel pump (which heats the fuel), into the engine compartment (which heats it further), and back to the tank. Diesel expands at roughly 0.05 percent per degree Farenheit and...

Well, I haven't a clue what the difference was between starting and ending fuel temperatures in Top Gear's mileage test. But neither do they, so I'll guess a number that makes the math easy: 25 degrees. That would give an expansion factor of 1.25 percent; times 10 gallons (the capacity of the Rabbit tank) is 12.5 percent of a gallon, or one pint. That’s not a factor to ignore when the line between success and failure is a pint and a third (as was in their case, where they were shooting for 70 mpg). Now we're comparing apples and honey bears.

By the way, this fuel expansion thing is not just theoretical. When Sharon Wescott and I won Escape from Berkeley (see Update No. 14), supporters had brought us extra fuel at the finish line. So we filled our under-the-hood tank to the top before we headed out of town. The fuel was veggie oil — I don't know its expansion rate, but it was greater than our fuel consumption rate. In Vegas traffic, we couldn't burn it as fast as it expanded — 15 minutes down the road we stopped to see if we'd sprung a leak, but no, oil was overflowing from the top of the tank. Imagine what fabulous gas mileage we could claim if we used the fill-drive-refill mileage measurement technique.

Browse previous MAX Updates.

Read the introductory MAX article, Here Comes the 100-mpg Car.

Visit the Kinetic Vehicles website for more technical details on MAX.

According to the U.S. Department of Energy, 1.2 billion gallons of gas are wasted annually due to under-inflated tires. By keeping tires properly inflated, drivers can improve their gas mileage by up to 3.3 percent.

 This Earth Day students at Loudoun Valley High School in Percellville, Va., have launched the enGAUGE It campaign to encourage motorists to regularly check their tires and keep them properly inflated. The students will hand out thousands of free tire gauges at various locations around the community and will provide demonstrations on checking tire inflation to community members, including local elected officials.

The Newton Marasco Foundation, an organization dedicated to inspiring the next generation of environmental stewards, is sponsoring the enGAUGE It campaign by providing the students with the tire gauges. The Foundation has also created a website for enGAUGE It that offers tips for checking tire pressure, a gas savings calculator and a tool kit for starting an enGAUGE It campaign in your area.

To learn more about checking your tire pressure and why digital gauges are best, read Check Your Tire Pressure and Improve Your Gas Mileage and Under Pressure: Better Tire Gauges Mean Better Fuel Economy.

The rules for the Progressive Insurance Automotive X Prize have been under development for some years now, and all us entrants are on pins and needles — waiting for their release. We've had looks at rule proposals all along the way, given to us in confidence. That's really been the only challenge I've faced as a combination entrant/journalist: there have been times I've had burn-after-reading documents and had to resist my urge to blab.

But now that the latest draft of the Auto X Prize Competition Guidelines have been made available to the public, I'm going to ask for your advice.

The final rules are pretty certain to require we meet a performance standard of zero to 60 mph in under 18 seconds. Not much under, 17.999 will do, but for MAX, that's going to be tough.

What? 18 seconds to 60 mph isn't very fast, but you'd be surprised how many vehicles on the road can't do it. Fully loaded, my four-cylinder Dodge Caravan can't do it, and while it's hardly a performance car, it's adequate. Anyway, this 18 second thing is a fairly recent requirement. It wasn't in the projections when we signed up, so we had designed MAX from the get-go to hit 60 mph in 20 seconds.

Why 20 seconds? Because that's in keeping with the low budget sports cars you could buy new when I was young (and quicker than some, such as the Bugeye Sprites and the Karman Ghias) and I thought it could be done today with a 100-mpg, low-budget sports car. I'll confess we haven't hit 60 mph in 20 seconds yet. On paper it looks like streamlining will get us down to that, so I'm not worried. Or I wasn't before … but I am now.

To increase acceleration to a given speed by 10 percent (in this case, from 20 seconds to 18 seconds) requires more than 20 percent more horsepower. To skim over the math, it would take 10 percent more thrust applied for the same length of time, but by definition it has to be accomplished in 10 percent less time.

1.1 squared = 1.21 so that's 21 percent there. Plus there's no acceleration happening when I'm shifting gears and I doubt I can shift gears 10 percent faster (if it takes me a quarter second per shift then we're really comparing 17 seconds of acceleration with 19 seconds of acceleration). And we don't have much besides horsepower we can mess with.

Make MAX lighter? That'd be nice, but it's not likely to happen given the weight of the additional crash protection structure we're installing.

So to put it simply, this upcoming performance rule is going to call for about 25 percent more horsepower than we have now. How are we going to go from the 32 horses we have to the 40 horses we need?

Beats me! But we're sure not giving up; we're going to find out. The first step of our research is to ask you. Got any ideas on how we can boost our power by 25 percent without hurting fuel economy? If so, please post a comment below!

Browse previous MAX Updates.

Read the introductory MAX article, Here Comes the 100-mpg Car.

Visit the Kinetic Vehicles website for more technical details on MAX.

It's too darn cold to go in the shop, and I have a lot of work to do. To hit our goal of 100 miles per gallon, we have to get MAX's drag down by about a third, and the only way to get there is streamlining. And to hit my personal budget goal (I want MAX to be a car you can reproduce at home for less than $10,000), MAX needs a simple body.

Jack McCornack

The practical problem with a slick sleek full fiberglass body is it's going to blow the budget — maybe not for me, 'cause I've built car bodies before and I'm willing to pay myself 35 cents an hour to build another one, but the Michelangelo technique (take a big rock and knock off everything that doesn't look like David) works better on paper than it does in practice. A full body from a commercial fiberglasser is going to cost at least few thousand, and if you don't live on the West Coast, how are you going to get it home? So we're going to try simple first ... or to quote Albert Einstein, “as simple as possible, but no simpler.”

The idea is fiberglass fenders — which have to be a bit complicated — with complex curves to direct the air over and around them, joined together by sheet metal body panels with simple curves. And thanks to the miracle of modern technology, I can work out the details in a warm house instead of a cold shop.

This particular miracle is Rhinoceros, a 3D modeling program with a funny name. When I build a real body to match the electronic/virtual body, I'll know the parts fit before I fit them.

Another advantage of working electronically ... you remember a couple months ago when I mentioned the crew from the Science Channel shooting a Brink segment about us? It'll be on tomorrow (Friday, Jan. 30), and they wanted some graphics right away of what MAX will look like when it's done. Well, maybe it'll look like this, kinda. Except with a roof.

P.S. I saw an ad for the Brink episode and it looks like it'll be fun. To look up when it will show in your neck of the woods, visit the Brink website.

Browse previous MAX Updates.

Read the introductory MAX article, Here Comes the 100-mpg Car.

Visit the Kinetic Vehicles website for more technical details on MAX.

If you have a bajillion dollars or a well-equipped university, you can determine a car's aerodynamic drag in a wind tunnel. But you don't, and neither do I, so we'll have to do it on the cheap. Champagne science on a beer budget, that's my motto.

Automotive wind tunnels work by blowing air at a measured speed over a stationary vehicle (or model) and measuring the forces (drag, lift and stability ... doubtless the source of those tailfins that started appearing on American sedans in the '50s) acting on the car via a number of scales under the tunnel floor.

It's a fine way to do things, and is quite comfortable for the technicians, who sit in a room outside the tunnel, who can wander off for coffee, and who don't have to worry about their notes blowing out of their pockets during the test.

For the MAX project, however, we're using a moving car traveling through stationary air, which presents two obvious problems: How do we measure the speed and how do we measure the force?

PHOTO BY KATHERINE LOECK

A car speedometer isn't sufficient for speed measuring — too vague and too inaccurate — but modern technology has brought extremely precise speed-measuring equipment to the masses: the handheld hiker's GPS. Not only do they measure speed, they measure position and date and time of day, and best of all, they record it for you. This is important because one disadvantage of doing aerodynamic testing in cars (and trust me, this is also critical when testing aircraft) is that the technician has to pay attention to not crashing, along with attending to the test.

I quit trying to multitask during test flights (and drives) nearly 30 years ago, when I started using an Apple II for data acquisition. I mounted it on a plank (a literal “on-board” computer) along with a motorcycle battery to run it, and a 5¼-inch floppy drive. It was big and cumbersome and costly and fragile and only accurate within 3 percent to 5 percent, depending on what I was measuring.

Who would have guessed that future sporting goods stores would have speed-time-and-distance recording devices for under a hundred bucks, accurate to 1/10 mph, and small and handy enough to take in the shower with you?

That yellow thing on the dash in the photo is a Garmin eTrex GPS, and I leave it running any time MAX is running. It records my last 600 miles or so of driving, and every now and then I download it to my laptop and examine the data at my leisure.

So that covers speed, but how do we measure the force? I’ll tell you the answer to that riddle next week. But in the meantime, I'll give you a hint: See that yellow light on the driver's side of the dashboard? That's the oil pressure light.

Wow, I'll tell you, the only people crazier than camera people are stunt performers ... and that's not by much.

Last week, we had a crew from the Science Channel at the shop (which is why you're not getting the promised wind-tunnel-without-a-wind-tunnel update 'till next week), shooting a piece for Brink.

PHOTO BY DAVE LEVISON

What's Brink? Beats me, I've never seen it. I don't get cable and besides, the series isn't on yet. From what they tell me, it's about people and things on the brink of scientific achievement. MAX is just the sort of thing they're looking for, so they ended up on our doorstep.

It appears the show is rather personality-driven, and the ideal personality for Brink is a low-budget mad scientist. I'm good for two out of three (I'm still a little weak on the 'scientist' part), so I fit right in.

Plus, I'm game and cooperative. So when they told me to stand by the car and look “seriously cool,” I gave it my best and didn't laugh. I was a fully poseable action figure, and in exchange, they let me talk about MAX and why we’re building it.

And then we went off to show how much fun MAX is to drive, with the camera woman in the passenger's seat. We hit some back roads and went zipping around in fine sports car style, until she decided she could shoot better from on top of the car. I agreed, but refused to zip, which is why those particular shots are going to look a tad reserved.

Next, she wanted highway shots from the front, which she took by sitting on the trunk of Dave's Miata while I tailgated in MAX. She took it all in stride, but I was sweating, hoping Dave hadn't waxed his car recently and wondering how quickly I could hit the brakes if she started sliding my way. Apparently this is the norm in show biz, but if a police officer had wandered by we would all have been written up for Acting Stupid in or About a Motor Vehicle. Need I add, kids, don't try this at home?

OK, fun's over, time to get back to work.

I am getting so spoiled. When MAX's gas mileage drops into the 50s, I get grumpy.

I wanted to put 5,000 miles on MAX before the weather got wet (next project — a convertible top), a somewhat arbitrary figure, but it's been my experience that 5,000 miles (or 100 hours) is enough to say, “Yeah, it looks like this is going to work.” So for me it's a benchmark. I made it, but it involved a lot of road trips, and those involved a lot of freeway flying.

The freeways are not my favorite environment — one reason is they tempt me to go too fast for fuel efficiency. At 70 mph, MAX is no more fuel efficient than a ... well, actually, there aren't any production cars that get better than 50 mpg at 70 mph.

MAX does (barely), so I guess I shouldn't kick myself too hard. But heck, MAX is supposed to be spectacular, not just good. With its upcoming streamlined body (currently in that gray area between the drawing board and the highway), it's going to be spectacular. But gosh, can't it be kinda spectacular and still have the look-and-feel of a classic sports car?

I sure hope so, because — I know, I know, I should be ashamed of myself — I'm greatly enjoying driving MAX around in its Vintage/Prisoner/Escape from Berkeley regalia. Everybody digs “Classic MAX”, and I love all the attention. Total strangers say, “Ooooh, that car is so cute, can I take a picture, can I get in it, can you take a picture with me in it?” and I know I'm going to lose some of that attention when MAX goes all streamlined and serious.

Sadly, the lovely, swoopy front fenders are part of MAX's visual charm, I say “sadly” because recent fuel consumption figures indicate that those fenders have increased MAX's drag at cruise by about 10 percent.

As you can see, those fenders make up a lot of MAX's frontal area, and that has to translate into lots of drag. I don't know how much drag, but there are ways of finding out. Tune in next week, and I'll show you how to do wind tunnel testing when you don't have a wind tunnel.

Photo by Jack McCornack

We hit one teeny snag in final assembly. As you recall, the original MAX got a significant swat from behind, which we feared might have affected the rear axle. Well, when we drained the lubricant from the axle, chunks of differential fell out. 

That’s not too big of a deal, since we had a replacement rear axle assembly waiting in the wings (I'll tell you why in a minute). But we hadn't wanted to use it just yet. In my opinion, the best way to do this "rebuild" would have been to make the new car exactly like the old car. Then we could have driven it, tested it and made sure our baseline hadn't changed — we'd know that any differences between the two cars were the result of a mistake. If there was any difference in performance or economy, we could sit down and figure out what we did wrong. If there were no differences, we could go back to our development plan of making changes one change at a time and testing the results. 

But the clock is ticking: summer is whizzing by and we have quite a long to-do list. The top job on that list is to install a taller rear end. That's hot rod slang for a final drive ratio that takes fewer turns of the engine per turn of the wheels, so at any given engine RPM, the car covers more ground. It turns out that the automatic transmission version of that Toyota Corolla wagon (aka the Corrode Warrior referenced in this article) has just what we need, a 3.30 (3.3 revolutions of the drive shaft = 1 revolution of the wheels) axle, so we went ahead and put it in MAX. 

I expect we'll see a higher top speed than with the original MAX — about 75 mph — and an improvement in fuel economy at cruising speeds. But maybe not. We may need to make streamlining changes before we see any benefits from the gearing changes. 

Meanwhile, we'll just have to trust ourselves that we haven't accidentally introduced any new variables, and the only difference between MAX version 1.0 and MAX 2.0 is the gearing. We should know soon. As you can see, the parts are falling into place.

Photo by Jack McCornack

MAX is coming back together, and we're now in final assembly mode. Time to plug the parts in the chassis. Here's the finished frame, painted a trendy and eye-catching gray. 

And we've used only the finest of materials and techniques — indoor/outdoor enamel from the local hardware store, the stuff with pictures of lawn furniture on the can. And we painted it with a combination of a spray gun for the big areas and a foam paintbrush for the nooks and crannies. It looks decent, in an industrial sort of way, but it doesn't look like something you'd see at a car show. It looks like something you'd drive. 

We gave it a coat of gray primer before we gave it the gray finish coat, but a lot of people couldn't tell the difference. 

"Are you primering it again?" 

Nope, this is the finish coat, it's glossier than the primer if you look close. 

"Gray, huh? This is how it's going to look when it's done? You're not going to paint it black? Man, you must have got a deal on gray." 

Nope, it's gray by choice, and the gray cost as much as any other color on the shelf. 

The reason car chassis are traditionally black is that black doesn't show grease and grime, thus pleasing the end user. But gray shows where oil is leaking, for example, and one man's grime is another man's diagnostic tool. 

Anyway, I wanted you to know it's gray on purpose, we didn't just spray on the primer and get bored.

Photo by Jack McCornack

This one's going in my wallet. It's the last pretty picture of MAX, on its way to a date with destiny. An hour later, MAX was in Eureka, stopped behind a van that had stopped for pedestrians, and the car behind me didn't stop for anything.

According to the accident report, the driver was progressing at a legal 30 mph and failed to notice that us other drivers weren't progressing at all. MAX is much shorter now, and wrinkly from stern to prow, since the impact from the back pushed me into the van in front.

So, what can we learn from this experience? We can learn how quickly we can make a new car, that's for sure. MAX is totaled, and though officially it's being rebuilt, it's going to be a bit like the joke about Abe Lincoln's axe:

“Yep, it's an heirloom, that axe has been in our family for 150 years.”

“Gosh, it looks brand new.”

“We've given it the best of care, generation after generation. My great grandfather replaced the handle, and my grandfather replaced the head.”

Or this could become like the true story of the Vin Fiz, the first aircraft to fly transcontinental across America back in 1911. It crashed and was repaired 22 times along the way; the only original parts left on the plane were the engine oil drain plug and one wing strut.

One lesson from this is it's better to sacrifice a car than a life. The front and rear of the chassis absorbed the impact as they crumpled, but the passenger compartment stayed its original shape, as did I. All in all I'm pleased with how well MAX “took one for the team.”

Another lesson is defensive driving is a full time job. I was stopped, in neutral, and I'd pretty much checked out of the driving experience. I had half an eye and about twelve neurons devoted to noticing when the car in front of me started to move, but otherwise I was giving my brain a little time off. In retrospect, I think the middle of the road is a bad place to take a break, and I should have been scanning for traffic despite being parked. Maybe it wouldn't have made a difference. But then again, maybe if I'd been pumping my brakes (and thus flashing my brake lights on and off) and screaming like a little girl, maybe my assailant would have noticed me two seconds earlier and saved us both a bunch of paperwork.

Live and learn. Now if you'll excuse me, I have a car to rebuild.

Follow our progress at Kinetic Vehicles and through the MAX Updates on this blog.

Small cars get better mileage than big cars. 

I know that's a gross generalization. I know a Bugatti Veyron is smaller than a Toyota Prius, but ...

A what? Yes, the Bugatti marque, reminiscent of racers in leather helmets wrestling with steering wheels the size of the ship's wheel on the Pequod, has been revived by Volkswagen, which is positioning itself as a performance car company. Hence the Veyron, their flagship sports car, with a price tag about $1.25 million higher than their Karman Ghia of yesteryear. But the Veyron goes three times as fast: a blistering 250 mph.

The Veyron looks cool, too. The seats are real leather and it has attractive cup holders and everything, but it doesn't get particularly good mileage, despite its smallness. And there's no reason it should — its target market is people who may be deeply concerned about fuel economy in general, but are totally unconcerned about their own gas mileage.

I don't hang out with a lot of gajillionaires, but I do acknowledge their argument about how they personally use fossil fuel: there just aren't that many gajillionaires, and their personal energy consumption is a drop in the bucket compared to the energy consumption of the billions of less fortunate folks.

I think the greatest damage done by the gajillionaire lifestyle is they set a bad example for millionaires, who then set a bad example for the rest of us. Our culture has been telling us our whole lives that we should live rich, that the trappings of wealth bring happiness, and that the image of success equals success. And a powerful car makes some powerful image statements, such as, “I am wealthy enough to get what I want, and this is what I want. And those dollar signs at the gas pump don't matter to me, what matters is having a car that will skedaddle when I romp on it.”

Lucky for the MAX project, the ultimate street skedaddlers are sports cars. The sports car is so well-established in our culture as a symbol of success — an impractical frivolity, a flaunting of one's disposable income — that any two-seat car looks like a luxury, and anyone driving one seems to be living the good life. I think that will be people's first impression when they see MAX, even people who turn up their noses at economy cars.

So thank you, Veyron. Thank you, Ferrari and Lamborghini, for flying the small-means-money flag. Folks won't know I'm a bunnyhugger, pennypincher, eco-cheapo-creepo until they read the fine print.

Naming our high-mileage project MAX was half in jest. The serious half is it's a condensed acronym for the Mother Earth News Automotive X Prize entry. The jest half is the implication that the car is big, a MAXimum car. The truth is it's really more of a MIN.

In my designs, I'm always thinking small. The pessimist says the glass is half empty, the optimist says the glass is half full. I say we're using twice as much glass as we need. It takes less energy to move small things than big things, and human transportation is one area where it pays to use the right amount of glass.

Need to move lots of people long distances? You can't beat railroads, though for person-miles per gallon, there are some busses that are pretty good. Need to move one person a short distance? You can't beat a bicycle, though there are some interesting electric vehicles that are close behind.

But our culture and our infrastructure — our millions of miles of roads, our cities and suburbs, our feed stores and tack shops that you can't get to by horse — are designed for cars, and that's not going to change overnight. We can, however, change our cars.

MAX is sized to perform the majority of automotive tasks, which is to move one or two people a moderate distance. For most driving in America, a four (or more) seat sedan is twice as much glass as we need.

A two-seater is not the solution to all automotive needs, we all know that. A 40-mpg minivan is more efficient than a 75-mpg two-seater, but only when the van actually carries four or more people. There are no points for potential efficiency because Car A could carry a bigger load than that of Car B. Actual usage is what determines efficiency.

If you have a crew cab truck that carries six passengers and a half ton of river rock while towing a 28-foot fifth wheel travel trailer and gets 11 miles to the gallon, that's pretty dang efficient when you're actually doing that stuff. But it's way too much vehicle for a trip to the grocery store. Unless you're picking up an awful lot of groceries.

Look for much more on the infant days of MAX in Here Comes the 100-mpg Car, from the August/September 2008 issue. And follow our progress through this blog, the Green Energy & Great Homes e-newsletter and my Kinetic Vehicles Web site.

Hello, I'm Jack McCornack, and this is the first blog entry in the chronicles of MAX, the Mother Earth News Automotive X Prize entry.

The Progressive Insurance Auto X Prize is a competition to develop high-mileage vehicles. You can read more about it here and here, but in brief, the target is 100 miles per gallon, and the cars have to be suitable for mass production. 

Oh, sure, the $10 million in prize money is attractive, but the big outfits say that's a drop in the bucket compared to what it takes to develop such a car. But then again, for an automaker, the publicity of winning would be worth much more than the prize money.

For Mother Earth News and me, the prize money doesn't matter because we aren't going to win any of it. We're in this to show what concerned do-it-yourselfers can do on a small budget, with readily available materials and present day technology. And if that's only 90 percent as good as the winners, well heck, I wouldn't mind driving a 90-mpg car that I built myself. Will it be suitable for mass production? You bet. In fact, it'll be so suitable for production that when we're done, we're going to tell you how to produce one of your own.

Last summer, I showed up at the Mother Earth News headquarters for the first time in a quarter century. While the faces had changed, the spirit felt the same. I met with Cheryl Long (the editor in chief) and John Rockhold (the green transportation editor) and we talked about old times. Even though this time I was the old-timer, the conversation followed a familiar path: what can we do to make things better?

Personally, I think Mother Earth News’ greatest contribution (cue the violin music) has been seeding our nation with (stirring trumpets enter here) folks who are happy with conservation (kettle drums, muffled snares), despite living in a culture where highest honors are given to (rim shot) waste and excess (whoopie cushion). Seriously now, how can people take pride in houses with 4,000 square feet of floor space per resident, and cars that get 11 mpg, and ...?

So after I stopped jumping up and down and foaming at the mouth, the editors said, “Yes! Let's do it, let's demonstrate that dramatic improvements in fuel economy are within reach. Jack, you’re the project manager — go for it! But please wipe that foam off your mouth, it looks creepy.”

And that's how MAX got started.

Look for much more on the infant days of MAX in Here Comes the 100-mpg Car. And follow our progress through this blog, the Green Energy & Great Homes e-newsletter and my Kinetic Vehicles Web site.

Stay tuned, this is going to be a heckuva fun ride.

Hybrids, electric vehicles, public transportation, bicycles and walking are good options for green transportation. But a small vehicle that gets up to 72 mpg and can go as fast as 45 mph seems like a good transitional step, too. Priced at less than $6,000, the Wildfire WF251-T deserves a closer look, even if it burns gasoline in its 248cc engine.

If you already have a Wildfire, please share your experience in the comments section below. And post photos at cu.motherearthnews.com.

These days, the morning temperatures in my area are gradually dropping like tree leaves. And thus begins a tradition for many: warming our cars before we depart each morning.

The trouble with this habit is that it wastes gas — a parked, running car gets zero mpg. You might as well burn your money. Plus, warming up is totally unnecessary — modern engines don't need to be warmed up before you start driving, unless the outside temperature is below freezing. The best way to warm up an engine is to drive it, gradually increasing in speed; no jack-rabbit starts. Even if it's below freezing outside, an engine really only needs 30 seconds to a minute of warm-up.

Nevertheless, the myth that it's best to warm up your car before leaving is widespread. One of my neighbors does this religiously — nearly every morning this time of year, I see his car running, parked in his driveway. Whether I'm running behind and leave at 7:25, or I'm on time and depart at 7:15, his Honda Civic is warming up, burning gas and pushing out carbon dioxide. Rather than just scrape off the bit of frost on his windows, he leaves his car running, with the defroster running full blast. It's too bad, because odds are that Civic isn't getting nearly as good of gas mileage as it could. (Oddly enough, I drive the same car, maybe even the same model year.)

So, spread the word — there's no need to warm your car every morning. Doing so wastes gas and money, and spews more global warming emissions into the atmosphere. I'll see you outside in the morning, scraping the frost off our windows, without our cars running.

For more info, read Should I Let my Car Warm up Each Morning? 

It's Friday. Time for another fuel economy pop quiz. This one should be easy.

  For better gas mileage, what should you do in the following scenarios?

• You're in line at the bank drive thru. You're three cars deep and there seems to only be one teller helping three lines' worth of cars.
• You're stuck in rush hour traffic. There's an accident ahead and nobody is moving.
• Your brother-in-law heads into the local pizza joint to pick up your carryout order.
• You're at the neighborhood mailbox and run into neighbors you haven't seen in weeks. They've got a brand new golden retriever puppy.

The answer: turn off your car. Doing so will be good for your gas mileage. Honestly.

Like the myth about warming your car during cold mornings, there's an all too common notion that it takes more gas to start a car than leave it running. The truth is it takes less than 30 seconds of idling to use as much gas as is burned when starting.

So this makes idling bad news for gas mileage — it's actually negative mpg because you're burning gas but going nowhere. Cars, SUVs and trucks with larger than average engines have it even worse, wasting even more gas when they idle.

So next time you're in one of the above scenarios or something like it, turn off your car when you'll be stopped for a minute or more.

In running errands or trying to get somewhere across town, the most direct route to your destination may not be the most fuel-efficient. So when pondering the best way to get to the grocery store or get home from the football game, ponder more than just distance and directness. Keep moving and you could improve your gas mileage, even if you're actually driving more miles.

 Pop quiz:

Considering the two options below to get to your local farmers market, which route should you choose for the best gas mileage?

Route A: A pretty straight shot from your house to fresh apples. About 13 miles. Goes through a quaint neighborhood with 20 mph speed limits and several stop signs.

Route B: Less direct, makes you circle around the back way. About 20 miles. Speed limit 40 mph for the most part. Only two stoplights (where you usually can turn right on a red light) between you and fresh free-range eggs.

The answer? Route B.

Anytime you can keep moving, your car will get better fuel economy. Even if it means driving longer, and especially if you can drive more in the sweet spot of about 40 to 60 mph. Frequent stops, and the subsequent acceleration from a dead stop, will hinder your gas mileage.

So seek out routes with less stoplights (or those where you can easily turn right on a red) and less starts and stops for stop signs, crosswalks, traffic jams, etc. Avoid idling and crawl-like speeds.

Also don't hesitate to adjust your route on the fly. Say you encounter a traffic jam or you're running late to work and you're behind the school bus that will make seven stops through your neighborhood — escape with the next turn you can make and go the long way around if you can get back on track without too much extra effort.

Personally speaking, I consider alternate routes as soon as I'm idling more than I can tolerate. Easy right turns can be a gas mileage miser's best friend.

Next time you change your oil or have it changed by a mechanic, be sure the new lube is the grade recommended by the automaker. Using the right viscosity (a measurement of the oil's thickness) of motor oil can improve your gas mileage by as much as 2 percent.

Even if the recommend motor oil grade is more expensive than other options, you'll save more over time in terms of maintenance and gas mileage with the right grade. Check your owner's manual to know which grade is best for your car.

Ever wonder what those letters and numbers in motor oil grades mean? For single grade oils, such as SAE 30, the SAE stands for Society of Automotive Engineers; the number after refers to the oil's viscosity.

But most current oils are multigrade, such as 5W-30. Multigrades use polymers and are designed such that you don't have to use a thin oil viscosity in the winter and a thicker viscosity in the summer. The W stands for winter, and the number paired with it reflects the viscosity during cold temperatures. The second number refers to the viscosity at higher temperatures. The lower the number, the thinner the oil.

It's Friday afternoon — do you know what's stored in your trunk?

Seriously though, many of us stow stuff away and forget all about it. Depending on the weight of what lurks in your trunk, you could be hampering your gas mileage. An extra 100 pounds of cargo can lower your fuel economy by up to 2 percent.

This is even more true if you drive a small- to medium-size vehicle — extra relative weight drags down smaller cars than the SUVs and trucks of the world.

Here's another twist on this problem: we weigh more than we should, and a lot more than we used to, and that makes the vehicles in which we ride less efficient. According to research by professors from the University of Illinois and Virginia Commonwealth University, Americans annually use about 1 billion more gallons of gas than in 1960.

Why? Because of the obesity epidemic in the United States. From 1960 to 2002, the weight of the average American increased more than 24 pounds, according to the U.S. Department of Health and Human Services.

Of course, this is bad for our health, but also for pocketbooks, oil consumption and pollution that causes global warming. Click here and here to read more about this study.

So, this weekend, it's time to finally unload your trunk full of recycling, books to donate, tools, bags of mulch or whatever else is hiding in your trunk. And hit the gym.

Green means go, but if you want to go with better gas mileage, don't bolt out of a red light or stop sign. You already know that speeding can reduce your fuel economy. Ditto for so-called 'jack rabbit' starts and other aggressive acceleration.

Gunning it from a dead stop can reduce your gas mileage by 5 percent. Flooring it when cruising on the highway can lower your mpg by 33 percent. These bad habits also increase emissions from your car.

So next time you're stopped at a red light or stop sign, or merging onto a highway, don't put the pedal to the metal. Accelerate smoothly and slowly. Make that a habit and you'll reap the rewards at the gas pump.

Here's another easy way to boost your gas mileage, and help maintain your car's engine to boot: change the air filter. Swapping a dusty, dirty air filter for a new one can improve fuel economy by up to 10 percent and result in gas savings of about 32 cents a gallon.

If you have your oil changed at Jiffy Lube or a similar quick lube joint, you know that they hit you up to change your air filter practically every time. Don't fall for it. And even if you do need a new air filter, buy one elsewhere and change it yourself — you'll pay about $5 to $10 for a new filter from an auto parts store vs. anywhere from $15 to $30 from the lube joint.

How often you should replace the air filter depends on where you live and drive. City slickers should probably do so once or twice a year, or after 12,000 to 15,000 miles. Rural residents or those who regularly drive on non-paved roads might need to change their filters more often.

For almost all cars, changing your air filter is easy — if you can turn a screwdriver, you can do it. Start to finish, you can change the filter in less time that it takes to wash your car. You probably won't need any more tools than a screwdriver; for many cars you won't even need that.

• First, decide if you even need a new filter. Park your car, apply the parking brake and pop the hood. Now locate the filter box — it's usually black plastic and is probably located on top of the engine or off to one side. The box will be held shut by screws or some sort of clasps. Open it up and examine the filter. Be sure to note how the filter fits in the box so you can put it back right or install the new one correctly.
• Most filters are some shade or red, orange or pink, and are made of stiff paper that look stacked like a hardback book with thick paper or folded tight like a nearly closed accordion.
• The filter might be really nasty and clogged and you'll know right away you could use a new one. But even if it's moderately dirty, you might not need to replace it. Gently knock it around to see how much dust and dirt you can shake out. Stretch and thump the paper folds to see what more you can get out and how much is trapped between the folds. You could even run a shop vac attachment across it (gently, of course).
• If after all that it remains really sooty, you're due for a new one. Be sure to clean out or vacuum out any leaves, dead bug remains, etc., out of the filter box.
• Next, put the filter back in (for now) or leave it out — it's fine to drive short distances without one plugged in, but do close the box. While your local auto parts store should be able to look up the right size filter for your car, it's not a bad idea to take your current one in with you to be sure you get a perfect match. 
• Last, drop in the new filter and close its case. Your car will now breathe easier and deliver better gas mileage.

Click here and here to see how-to videos of this process.

Over the years I've heard several different versions of this conversation:

It seems like I'm buying gas more and more often these days. I'm assuming my gas mileage is declining, but I don't know why.

Have you checked your tire pressure recently?

Tire pressure? They look fine, why would I need to check their pressure? Why would it change?

Unfortunately far too many of us drive every day with the assumption that our tires are properly inflated. Thirty percent of us, according to the National Highway Traffic Safety Administration, have at least one tire that's low by 8 psi or more. This is bad news for fuel economy and our consumption of oil — we annually waste 1.2 billion gallons of gas according to the U.S. Department of Energy. Bad tire pressure also increases the odds of blowouts and other types of tire failure that can be a real pain, if not a serious risk to safety. 

So, when was the last time you checked your tire pressure? Two months ago? Six months ago? Ever?

Here's the good news: checking your tire pressure is easy as checking your oil or filling your gas tank. Here's the better news: keeping it right can have a significant impact on your vehicle's fuel economy, a kick of up to 3. Keep it right and you'll have to buy less gas, and the savings will ultimately amount to paying about 10 cents less per gallon. So, for safety, savings and fuel economy, checking your tire pressure ought to be a fundamental strategy in the game that is getting better mpg.  

For numerous reasons, our tires generally lose about 1 to 2 psi every month. Lose 1 psi in all four tires, and your fuel economy will fall by 0.4 percent. So get a digital tire pressure gauge and use it every month.

It's important to check the pressure when your tires are cold, which doesn't mean when it's cold outside but rather a few hours since they last pounded the pavement. If you live near a gas station with an air pump, the simplest thing is to check your pressure before you go, then get air there if need be. If you have to drive several miles to get to an air pump, check your pressure again when the tires are warm to give you a relative change form the cold reading that will tell you how much more or less you need to put in.

Why a digital gauge? As cool as I thought the pencil-style sliding stick gauges were when I got my first as a kid, I quickly realized they'll give you different readings just about every time. Digital gauges are far more accurate and easier to use. Click here to read more about them.

How do you know the right pressure? Look for a small sticker near or on the driver's door or in the glovebox. It will tell you the idea cold pressure for your vehicle. Sometimes there will be one number for the front tires and another for the back. Either way, that's the number you want; don't be tempted by the number actually stamped on your tires. It's the maximum pressure those tires can handle.

When it comes to saving money on gas and improving mpg, it doesn't pay to get where you're going faster. While every car is a little different, the general truth is that fuel economy nosedives when you cross the 55 to 60 mph threshold.

Check out the graph on this page from fueleconomy.gov. It looks like an eastern Kansas hill — there's a sharp rise, a brief plateau, then a sad decline. The sweet-spot for fuel economy falls between about 40 and 60 mph. For every 5 mph over 60 you drive, the site says, you're basically paying an additional 20 cents more per gallon for gas.

But in today's fast-paced America, slowing down can be tough. Even though driving faster (say 75 instead of 65; 55 instead of 45) rarely saves an appreciable amount of time, it's hard to break the gotta-get-there habit. Plus, few people enjoy the glares and obscenities that often come from those annoyed because you're going 5 mph under the speed limit instead of 10 mph over. Nevertheless, you'll get a good rise in mpg if you consistently lock your cruise control on the speed limit, or even just a little under, for high-speed driving. Just take the slow lane (think of it as the scenic lane) and remind yourself how much gas and money you're saving as the rat race flies by.

As you might guess, changing our national speed limits would be a game-changer for saving oil. We've been down that road before: the change to 55 mph was a key factor in reducing our oil consumption in the 1970s. Should we do that again? Post a comment below to share your thoughts.

One of the best ways to save money on gas and improve your fuel economy is to not buy gas you don't need, or can't even use for that matter. The easiest ways to do that is to not top off your tank.

It's a bad habit for many people — after the pump shuts off automatically they think they can squeeze more gas in their tanks or they want to get the cost to a round number. But the truth is the nozzle knows when to stop. Trust the nozzle. Here's why:

• Most gas stations' nozzles have sensors that shut off the fill up when the sensor is covered with gas. Anything you pump after that either goes back into the station's tanks or will spill out for the next person who uses the pump. All that extra gas does not end up in your tank. And excessive topping off could damage the pump's sensors, which will lead to more gas being pumped than is necessary, which leads to more waste and emissions. It's a vicious cycle.
• When you spill gas from overfilling or leave gas to squirt out on the next person in line, that creates vapors that are harmful to breathe and contribute to air pollution.
• Your car's gas tank needs wiggle room because gas expands as it warms. Too much gas in your tank could damage your car's vapor collection system and cause your car to run sluggishly and produce more emissions than it normally would.

Want more gas for your money? Whenever possible, fill up when temperatures are relatively cooler. As temperature rise during the warmer times of the day, especially in the summer, gas expands and thus you get a little bit less as you fill up.

But in the morning or late evening, gas has more density and you'll thus get more for your money. Cooler temperatures also mean less evaporative emissions from your time at the pump — smog forms more easily when it's hottest outside.

Another good reason to buy gas in the early morning: It's speculated that gas stations, especially the corporate chains, adjust their prices in the late morning or at lunchtime. When those prices go up, that starts a domino effect for all the locally owned stations in the area.

The first step to improving your car or truck's fuel economy is to know how many miles per gallon it really gets. Calculating mpg is easy, even if you hate math. Plus, monitoring your fuel economy and becoming more aware of what influences it is one of the simplest ways you can make a difference for the environment and your wallet.

Here's how to do the math. It's easier than you might think.  

1. Fill up your tank.

2. Reset your trip meter to zero.

3. Get gas when you need it.

4. Record the number of gallons it took to fill your tank and the number of miles on your trip meter. You could write these numbers down in a small notebook, or perhaps an easier place is the gas receipt. Usually these already include the number of gallons you bought.

5. Reset the trip meter before you restart the car (so you can check your fuel economy again next time).

6. Divide the trip miles by the gallons of gas. Congratulations, with just simple division, you've calculated your car's mpg. For example: 298.7 miles ÷ 8.475 gallons = 35 mpg.

7. Whether you use a small notebook or a simple spreadsheet on your computer, track your fuel economy over time. It can be fun and rewarding, especially as you learn habits to improve your mpg. It will also give you a better understanding of how your car is performing and can signal potential maintenance needs before they become big problems. If a few calculations reveal dramatic declines from the norm and you don't have an obvious explanation, consider calling your mechanic. Another idea is to record basic notes on fuel economy influences such as speed, tire pressure, driving conditions, extra loads and use of air conditioning. This will help you better understand what driving habits most influence mpg. Tracking fuel economy will also give you a richer understanding of just how much money you spend on gas and how much oil driving requires.

Now you know how to do the math. Make it a personal challenge to improve your fuel economy. Tell us about calculating your mpg, and improving it, in the comments section below.