Info on Motor Oils...

[Wayne 962]

I found this info on another website - I've written about this before:

Consumer Reports, with one of the most widely respected product testing laboratories in the world has just released the results of an extensive test on oil brands and oil changes, as well as other issues regarding car care. In the process, the test demolished much of the conventional wisdom regarding car lubrication. The two most surprising results: the frequency with which oil is changed doesn't matter after the first few oil changes on a new engine, and the type or brand of oil used can not be shown to make any difference.

The testers placed freshly rebuilt engines in 75 New York taxis and then ran them for nearly two years, with each cab racking up 60,000 miles, placing different brands and weights in different cars and changing the oil at 3,000 miles in half the cars and 6,000 in the other half. At the conclusion of the test period, the engines were torn down, measured and inspected. The conclusions: Regardless of brand of oil or weight, no measurable differences could be observed in engine wear. Furthermore, there was no difference among cars which had oil changed at the shorter or longer interval.

Does this have any bearing on the enthusiast's car, which is given almost the opposite usage stored for long periods of time then started and driven for short distances? The tests suggested that our type of usage would build up sludge and varnish, indicating that an annual or semi-annual oil change is a good idea regardless of how much mileage the car is driven. But there is little indication that the brand or weight needs to be given serious consideration, and synthetic oil has no discernible advantage over the old stand-bys. More information on the tests and results can be obtained from Consumers Union or the July issue of Consumer Reports available at most libraries.

[rfng]

I guess the commercial "motor oil is motor oil" is true.

[Quicksilver]

I don't know if 60,000 would constitute a valid test on any reasonably modern motor. Parts really don't show any real wear (other then basic break in) until they get right up to the point where they go into failure mode.

For the test to really show something you would need to run something into the last 1/4 of its engine life.

Also I would expect a taxi to be started up and left running the whole day, which is the easiest wear that you can put on a car. It doesn't include thousands of cold starts and warmup periods. I would expect minimal wear from their test. I would be more interested in a test that has more cold starts, shorter run times, and more time sitting. The hardest thing on oil is the moisture from condensation collecting in the oil and not having enough running time to boil it out. It tends to promote the formation of acid compounds in the oil.

Example: In the 70's you could expect 80 to 100 thousand miles out of a cam in a Chevy 454. My father was a GM parts man in Alaska in the 70's and during the construction of the Alaska pipeline he saw an extremely large number of 454 powered trucks that needed their first parts replacement at 200,000+ miles. The reason was that they were starting the trucks and running them 24 hours a day without turning them off (Even to be fueled! It gets cold up north!). When the engine is warmed up none of the metal parts touch each other, even with the old oils that were available back then.

Wayne

[beepbeep]

OK, that's does it. From now on I will only drive on dyno oil. It will keep my car leak-free and I bet it's really good in these conditions: