psneeld
Guru
I'm sorry but I can't agree with this 100%. It may have been true for an engine that was built in 1970 but remember the engineers didn't have at their disposal the things that are at the disposal of engineers today.
As an example what if you had a heart attack today and the Dr. that came into the room to treat you was 90 years old and he said "take two aspirins and get a lot of bed rest" because that was the way they did it when he got out of medical school in 1950. Would you do that or would you like to have the triple by pass, or valve replacement that has saved so many people in the last 40 years?
The point is that there are oils and lubricants that are available today that were not even thought of when your engine was built so there was no way for the manual to recommend them. Read the side of the can. If it meets or exceeds the SAE Specs for your engine it will not hurt your engine.
I agree with the above...the oils of today are far beyond what was available in the 70's. Lehman's ran forever on crap oil of the 70's so it's easy to say "why change what ain't broken".
Some guys laugh at SuperTech oil from WalMart...but an independent lab showed it to be superior to many big name oils in many applications.
I'll bet if I ask a bunch of engineers and mechanics if it's OK to use WaMart oil they would probably give me a dozen reasons not to...but ask a bunch of petro-chemical chemists and they might say different.
My boat engine gets babied compared to my diesel truck...because my truck engine is flawless after the 12 yrs I have owned it and it will probably do another 12...I don't see how a lehman loafing along at 1600 rpm is going to be hurt by almost any decent oil.