ZDDP in API oils used in PRV engines

Y'all,

A post in another car forum warned of a shortcoming API rated oils may have
regarding cam wear. The question relates to lubricating oils with reduced
zinc dithiophosphate (ZDDP) in engines. http://www.ttalk.info/Zddp.htm

Since the most sensitive engine I know is the pre-88 PRV engine, I was
looking for the group's input on that.

Thanks!

Mike

 

If I had one, I would only run a quality full synthetic in it, it's not
worth taking chances.

 

The link purports to warn us the current API oils (mineral or synthetic)
lack enough ZDDP to protect flat tappets. I haven't heard of problems but
figured PRV owners would be up on the status of the oil they use.

 

There is much talk about this in old car circles these days. Perhaps
the most reasonable advice I have seen is to use the dual rated
diesel/gasoline fleet oils such as Shell Rotella (or Rotella T
Synthetic), Chevron Delo and the like. These are readily available in
15W-40, which is a good summertime oil in many older applications and
can also be found in 10W-30.

 

Thanks, John. That does sound reasonable.

Mike

 

ZDDP isn't the only antiwear agent that is effective...it is just the
cheapest. It is also an effective antioxidant. There are substitutes,
including Molybdenum Trialkyldithiocarbamate, but they cost more.

A dual diesel/gasoline rated engine oil, either 15W-40, 10W-30, or
synthetic 5W-40 is a cheap, easy, effective alternative for these older
engines. Modern engines have no problem with modern oil. For a modern
gasoline engine, the dual-rated CJ-4/SM diesel engine oils will work
very well due to the lower level of ash producing metallic detergents in
the oil.

Ken