Consumer Reports on Oil (kinda long)

[gregsj@mail.imm.com]

Fellow Audians: for what it's worth, the following oil report appeared 
in our Saturday paper.

Report Says Motor Oil is Motor Oil. Test by consumer watchdog reveal 
only minor differences.

AP--New York--Premium Motor oil and fancy additives are nothing more 
than slick sales Consumer Reports says. The consumer watchdog tested 
20 types of motor oils under the most grueling conditions--in a fleet 
of 75 NYC taxi cabs--for nearly two years. The results: there is 
little difference among brands as long as the container carries the 
starburst symbol--a standard set by the American Petroleum Institute 
for additives needed to keep modern engines running. The study also 
found:

For normal service, changing a car's oil every 7,500 miles, or at the 
automaker's suggested interval is sufficient. Although some mechanics 
recommend oil changes every 3,000 miles, it only wastes money and adds 
to the nation's oil disposal problems. Consumer Reports cautions, 
however that no oil, synthetic or conventional, should be used for 
more than 7,500 miles or the maximum interval recommended by the 
automaker.

Expensive synthetic oils worked no better than conventional motor oil 
in the taxis, which drove 4.5 million miles in stop-and-go traffic. 
But synthetic oils may be worthwhile for cars in extreme driving 
conditions.

Additives such as Slick 50, STP Engine Treatment and STP Oil Treatment 
failed to show a significant reduction in friction and engine wear 
compared with engines using the same oil without the additives. 
Consumer Reports said additives are unnecessary as long as the oil 
used meets the API standard

When using a quick-lube center, tell the mechanic what grade of oil 
the owners manual recommends. Consumer Reports found that unless told, 
the quick-lube shops failed to use the proper grade about half the 
time.

In addition to the tests in the Chevrolet Caprice taxicabs, the survey 
analyzed the characteristics of each oil in determining its findings. 
Motor oil should be thin enough to flow easily when the engine is cold 
and remain thick enough to provide protection when the engine is warm.