dieselenthusiast wrote:
Actually, if you really take care of an engine, gas or diesel, it can go far beyond what you can imagine. I’ve seen gasoline engines go well-over 300,000 miles without a rebuild or overhaul. And I’ve seen diesels hit the 1 million mile mark. A Saab from the Northern Midwest (United States) just went over a million miles, and Saab gave him a brand new car. The million mile car is now in a museum. There are plenty of old Mercedes 300D's in the Million Mile Club verified with the original engine and without an overhaul. I’ve heard of several Dodge Cummins owners going over 1 million miles. I’ve known one guy personally in Deming, NM who had a 1998 Dodge Ram 12V inline 6 Cummins who rolled over 1 million miles. I thought the truck was going to fall apart, but the motor kept going. Diesels are still new to North America and have not has the opportunity to be on the road long enough to reach 1 million miles. People who buy VW diesels aren’t driving them 30,000 miles a year. Give the VW Jetta another 10 years and you might start seeing them show up with 1 million miles. With synthetic oils, by-pass filters, better fuel supplements, various aftermarket components, better educated people, and with the new popularity of a diesel driven world, I suspect that diesel engines will continue to rise to the million mile mark. Diesel engines last longer because Diesel fuel is a lubricant and assists the oil circulating through the sump, block, and heads. Gasoline, however, breaks down oil. Any piston seal blow-by or valve seal leakage will cause the oil to break down and leave critical metal components to rub against each other. This is why I like Diesels, they are more efficient. This is also why biodiesel is so important. The biodiesel is the best known lubricant and cleaner on the market, and has been for over 100 years.
I wholeheartedly agree that taking good care of your engine will keep it running much longer than many others which haven't been kept in such a good condition always. I have some remarks to your other points, however.
Diesel will also break down your oil. Anything from the exhaust system will crap that oil in no time. Why do you think so many people have problems with the EGR valve and wants to get rid of it?
Diesel fuel has lubricating properties? As much as gasoline has. Diesel is assisting oil lubrication? Not true. Diesel breaks down the oil just as gasoline does, and metal parts form in the oil which rubs against everything, just like in a gasoline car. Why do you think we have oil filters?
Diesel is not some god saving power. The main reason why diesel cars lasts better is because the engines are built tougher. The compression ratio of a diesel engine is far greater than a gasoline car, most likely 1.8:1 or even 2.2:1. This is one of the reasons why diesel engines blocks are built in cast iron. Another reason is the higher torque output which requires stronger materials.
Diesels ARE more efficient because of higher temperature burns and also higher compression ratios. In addition to that diesel fuel contains more BTUs than gasoline AND diesel weighs more per liter than gasoline. Glad we don't pay per unit of weight but by unit of volume.
Actually when Rudolf Diesel designed his engine he was not going for an engine to burn petro-diesel but for an engine which would run on many alternative fuels. I am sorry that we cannot use this potential of the diesel engine properly because of the auxillary systems around the engine can't handle the more aggressive types of fuel.