In Reply to: Re: Which engine oil is the best? (more) posted by Carl on November 22, 1999 at 18:16:05:
I thought it was interesting, but questioned if the test method would directly correlate to how most people drive their cars. In the test, they used a fleet of taxis. They were started up and would run all day long, so their oil was at operating temp almost all the time. I would like to see a test where they take short trips, turn off the car, and the engine fully cools before restarting. This could make a difference in contamination levels, and therefore wear.
I thought that they only went 60k on the motors (I could be wrong, been a while). I'm not sure that wear in an engine happens at a linear rate, and they may not have gone far enough to see differences. I would be curious to see if there were mesurable differences once you get to higher milages (say 150k?).
: Consumer Reports did a big test on all the oils and the intervals in between changes, and if I remember correctly, they could not find any difference between any of the oils or any "real life" advantage to synthetic oils. The test consisted of running several motors for 100k and measuring the parts before and after the test for engine wear. They also stated (if my memory is correct) that it was a waste of money to change oil at 3k intervals (as opposed to 7.5k) as all the quick change places recommend. I don't know how much I would buy into this article, but I just thought that I would throw it out there as information.
: : I had my 328i engine oil replaced at BMW dealer with odometer reading of 7800 miles. They used Castrol 5w40
: : on it, and they put a sticker for the next replacement of 11800 mile. Any opinion if there're better engine oil than Castrol like Mobile? Also, I don't understand why dealer marked 11800 mile for the next oil change while official BMW recommend the first oil change at ~15K miles.