(snip)
Also, even if synthetic is better, the dirt is the killer. Carbon, dirt, etc. will always get into your oil. How much of this will accumulate during 25K miles!!!!!!!!!!!!
(snip)
Sheesh. You guys gotta be smarter than this.
The oil filter traps that dirt.
Even if one chooses to use a premium synthetic and an extended drain interval, you still need to change the oil filter every 3000-5000 miles.
While I've used Red Line 10W30 with extended drain intervals for about the last ten years, under normal conditions, never have I run the oil more than 16,000-18,000 miles or for more than a couple of years. Under one-time test conditions, I ran RL 10W30 to 22,000 miles w. filter changes every 3000-4000 miles. Consumption in this test was 3000 miles per qt. After that test, spectrographic oil analysis indicated the oil had just about reached its life expectancy but was still servicable.
Anyone changing oil every 3000 miles is 1) living in the 1950s and 2) has been completely indoctrinated by the quick-lube oil change business' marketing B.S.
If you don't use a premium synthetic or don't care for extended drain intervals, my suggestion is to use at least the oil recommended for your car and change it at the recommended interval but....change the filter at half the interval. In the case of cars with oil life moniters, observe the moniter. It's even better than changing oil by mileage. On a C4s with oil life moniters, where the moniter does not read digitally, change the oil at half the oil change interval. On a c5, change the filter at 50% life.
As for Slick 50---that stuff is nothing but a marketing scam.
Years ago, DuPont tried to go to court to prevent the company which manufactures Slick 50 from marketing it for use in automotive engines. DuPont lost. Seems that, if the company that invented Teflon (the key ingrediant of Slick 50) feels it should not be used in internal combustion engines, then there's a problem somewhere.
As for Mobil One's marketing claiming it's been run to 100,000 miles with filter changes, know that Mobil 1 will not go anywhere near that far under normal conditions. However, put it in an engine that has high oil consumption, run the engine under lab test conditions and change the oil filter regularly and you'd be able to run 100,000 miles without an oil change----at least not an oil change where one removes the drain plug, drains the old oil out and puts new in. If you can find an engine that uses about a qt. every thousand miles or so, the oil you put in to replace oil consumed would keep the quality of the oil such that it could last 100,000 miles.
As for the record run and Morrison Motorsports use of Mobil 1 for setting that record. I was the only media present at that event. Yes, Tommy put Mobil 1 in that engine---heck, he was sponsored big-time by Mobil Oil back then, but remember, the engine that car only ran 5000 miles and, at that, ran most of the 5000 miles at engine speeds and loads quite a bit below the LT5's peak. That was not much of a test of oil.
Not to say that Mobil 1 a good product--on the contrary, it's a fairly good, synthesized hydrocarbon synthetic--but this is to bring a little reality to this thread.
