You wanted it, here it is, Remember this is Not Someone’s “Research” This is an Actual Test!
Consumer Reports
The surprising Truth about Motor Oils!
ACTUAL TEST not someone “research”
I can’t find the actual Article on Consumer reports but here it is reported on another site!
Consumer Reports:Truth Motor Oils- July 1996
Recommendations
None of the tested oils proved better than the others in our tests. There may be small differences that our tests didn't reveal, but unless you typically drive under more severe conditions than a New York cab does, you won't go wrong if you shop strictly by price or availability. Buy the viscosity grade recommended in your owner's manual, and look for the starburst emblem. Even the expensive synthetics (typically, $3 or $4 a quart) worked no better than conventional motor oils in our taxi tests, but they're worth considering for extreme driving conditions high ambient temperatures and high engine load or very cold temperatures.
On the basis of our test results, we think that the commonly recommended 3,000-mile oil-change interval is conservative. For "normal" service, 7,500-mile intervals (or the recommendation in your owner's manual) should be fine. Change the oil at least that often to protect your engine and maintain your warranty. Even for the severe service experienced by the taxis in our tests a 6,000- mile interval was adequate. But some severe service - frequent cold starts and short trips, dusty conditions, trailer towing - may require a shorter interval. Note, too, that special engines such as diesels and turbos, which we didn't test, may need more frequent oil changes.
We don't recommend stretching the change interval beyond the automaker's recommendations, no matter what oil you use. Engine combustion contaminants could eventually build up and harm engine parts.
As for STP Oil Treatment, STP Engine Treatment, and Slick 50 Engine Treatment, our advice is simple: If you use an oil with the starburst symbol, you don't need them.
