MAX Update No. 49: This Diesel Tachometer Is a Small Miracle

| 6/9/2010 4:48:20 PM

Tags: MAX, 100 mpg, rally, gas mileage, tachometer, tach,

I was talking with Bill Bushholz of the Maine Automotive X Team about the upcoming Rally Green ...

Rally Green is a long distance fuel economy rally/demonstration for high-efficiency vehicles, which will take us participants (why yes, of course MAX will be there) from Iowa to California, through amber waves of grain and purple mountains majesty, on public roads and in plain sight to anybody who wants to watch (in marked contrast to the approach of the Progressive Insurance Automotive X Prize competition). I'm all excited, and so is Bill, who is organizing the event.

So after the Rally Green part of the conversation, we were sharing some tech talk and Bill asked if I had a tachometer. A tach is a useful item when you're trying to coax more miles out of fewer gallons, but they're not easy to come by for us diesel drivers. If he'd asked me a year ago, I'd have told him how I made an airplane optical propellor tach work by putting white and black duct tape on the crankshaft pulley, to simulate the flicker of propeller blades. It got me by, but it was finicky and expensive and I had to push and hold a button every time I wanted an RPM number, but now ...

“You bet,” I said, “It's what I drive by. It's digital, so it's easy to pick an RPM to cruise at.”

“Digital?” said Bill.

“Yeah, a Tiny Tach. They make them for diesel now.”

Jack McCornack
6/26/2010 2:41:55 PM

Hi Jan, mine came back-lit from the factory. You must be using a gasoline version Tiny Tach, which doesn't need an external power supply (and thus doesn't have power to run internal lighting). The diesel version, which you can find at... ...needs a power source for its tiny little brain, so as long as they've got power coming in anyway, they back-light the tach display. I'll send them a link to your comment, I expect they'll be interested.

Jan Steinman
6/25/2010 4:16:21 PM

The Tiny Tach is indeed a marvel that I have just one issue with: no light! It would be twice as great if it had an option for backlighting the display. While they're adding that, bring it out on another wire that could be powered by your headlights. I got tired of getting out the flashlight while driving at night, and eventually installed another tack -- with backlighting, wired to the car headlights.

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