The Longevity of Diesel Engines

| 4/4/2012 2:10:33 PM

Tags: diesel engines, diesel fuel, Todd Kaho,

Gary MuellerI’m thinking about buying a diesel truck and I’ve heard stories about how long the engines last. Can they really go several hundred thousand miles? 

While no engine will last forever, diesel engines have a distinct advantage in longevity over their gasoline counterparts. Mechanical parts wear out over time due to the friction caused by parts rubbing together. Diesel engines, however, are engineered and built to be more robust due to the higher compression ratio in the combustion chamber and the high torque output they produce. Diesel engines also operate at lower speeds (rpm) than gasoline engines, which means the bearings, piston rings, cylinder walls, valve train, etc., don’t rub together as often. Engine speeds are often half that of a gasoline engine.

These durable diesels are more expensive to purchase than a gasoline vehicle. But much of that investment can be returned when you trade or sell the diesel because they hold their resale value much better than gasoline cars and trucks. The transition to a diesel is easy — the only real difference is you pump diesel fuel rather than gasoline.

With proper lubrication and routine, basic maintenance, a diesel engine can last far more miles than a gas engine. Consider the example of retired Ford employee Gary Mueller (see photo). After his career at Ford, Mueller wanted to see the country and found a way to do so via taking a job delivering recreational vehicles by towing them on large, heavy trailers.

In 2002, Mueller purchased a Ford F-350 Super Duty pickup powered by a 7.3-liter Power Stroke diesel engine. The miles added up quickly. People started suggesting he trade the diesel pickup for a new one when it hit 300,000 miles. In 2011, the truck topped 1 million miles, and the original diesel engine is still running strong.

 Todd Kaho, Editor and Publisher, 

8/31/2017 8:17:36 PM

"But how much did he spend on fuel for those million miles?" Probably a lot less than a similar powered gas truck would have spent on gas towing recreational vehicles on large trailers.

peter fittipaldi
8/3/2012 4:00:31 AM

But how much did he spend on fuel for those million miles?

jim peterson
5/11/2012 7:22:10 PM

One CRITICAL variable of what are called "high speed diesels" -- the kind used in trucks and pickups -- is whether or not special coolant additives are used (contact any big truck dealer for details). Without the additive, pinholes which begin on the coolant side of the cylinder wall can bore completely through the cylinder wall and potentially destroy the engine. Dry sleeves (to rebuild a damaged bore) are expensive, don't cool properly, and don't always effect a permanent repair. To compound the issue, there is NOTHING about this in Ford's owner manuals OR any of their online resources for owners. They want buyers to think diesels are no different -- just pour the fuel in and go! It's not that simple and Ford should be told to quit underestimating the collective intelligence of their customers. But until someone can prove that Ford knows better AND gets a sizeable settlement from them, nothing will change.

t brandt
5/4/2012 10:16:49 AM

Both comments are true and add to that what the author of the article said: diesels are built to tougher specs (ie- more expensive) in the first place. Most of us don't care to keep a vehicle for a million miles, so the point is really moot. The life of a gas engine can be exptended condierably by just changing the oil every 3000 miles and it can last forever by using a mineral oil based additive. (also gives you +5mpg).

mike rullman
4/28/2012 6:50:36 PM

Gas engines run on a solvent, diesels on a lubricant,

carl stettler
4/17/2012 7:43:20 PM

Also I would like to add that there is no gasoline (hydrocarbons) blowby to degrease the oil.

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