Re: Which V8 engine oil?

Posted by Jack Vines On 2008/6/25 10:07:21

Lots of opinions on oils. Here is an excerpt from a recent thread from the Studebaker Driver's Club Forum posted by Jeff Rice:

I spent a good part of today at a HD truck dealer open house plying my trade...The guy in the next booth was the senior technical trainer (ie: real smart guy chemical engineer) for Chevron Oil. I peppered him with all of the zinc of the week questions I could come up with. He has written several informative articles (without marketing hype) regarding the 'new' oils, the 'old' oils, the 'zinc' issues, and what the market is hyping to the old car folks...

Shell Rotella diesel oil... "Why in the world would anybody run diesel oil in a gas engine?"
Zinc supplemental additives: "Ask the oil manufacturer if they will stand behind their oil if you add a zinc supplement to their oil....They won't.."
Zinc 'reduction' in current oil: "Zinc hasn't been totally removed from current oils... It has just been reduced. Other compounds have been added to the oil to prevent scuffing problems.
Oil testing: The current test method (latest and greatest...I don't recall the official test number right now)is done on a Nissan flat tappet engine.
(What does this mean?)
It means that the latest engine oil sold today will NOT wipe out your camshafts or tappets.
It means that adding a supplement will not make things magically better...
It means that the engine oils marketed as 'vintage engine oils' are no better than any other oil, but are a whole bunch more expensive...
20w50 oil is fine to use in older engines, as the 20w 'cold pour point...(at 0 degree's)will be just fine in older engines. The 50 number actually 'seems' more like 30w due to the long polymer chain additive that gives it the higher number...
Gospel?
Don't know, but I asked for some followup from him to help us all out with good info... Biased info? Maybe, don't know, probably not.
He didn't have anything to gain by trying to sell me anything.
I found it fascinating...
Hope the info helps...
Jeff