What we have here.....is a failure.....to...communicate.....

Oil analysis from our old diesels has proven that the only valid concern with extended oil change interval is soot buildup. Soot, which is 0.03 microns in size, is completely harmless to an engine because it's just too small to be a problem. As long as the soot doesn't clump up and therefore grow in size, the oil works like it's specified and the engine will suffer no ill effects.

If the additive package can't prevent the clumping, then we have a problem. The newest, low emission diesels have EGR which increases soot in the oil. Therefore it was highly desirable for the oil companies to formulate oil that could handle to soot. They have. Amsoil has an oil that they claim can handle 10% soot without clumping. The other diesel synthetics run anywhere from 4 to 6%. Generally speaking, our engines with decent fuel will put about 1 to 2% soot into the oil in 10kmiles.

And, to complicate it a bit more, if you have to top off at any time in the cycle, the additives are replenished.

The Europeans think our oil change intervals are absolutely crazy. Oil there is a lot more expensive. Changing the filter and topping off is a very common practice. Studies have shown that they don't wear out engines any faster than we do.

The 3kmile change is a myth that needs to die. There's just no need for it. Unless, of course, you're running an oil change place, or a dealership which likes to work the pin action on oil changes. Typical scam....get them in on a cheap oil change, and then work other issues at the going rate....

There's one born every minute.

240Joe