hacker-pschorr

Right...that's why I said "reduced levels". There is a common misconception that most oils are void of all ZDDP when in fact they all contain at least 600ppm if not 800ppm. This really puts into question the whole theory of ZDDP killing CATS, that was my point. I wasn't advocating someone should use these oils in their air cooled 911.

I was also pointing out that I have yet to find a US available synthetic oil in 15w-50 / 20w-50 with the lower levels of ZDDP. Even Mobile 1 has 1200/1300 ppm Phosphorus / Zinc. If that is the target viscosity for the cars in question, people can relax a bit when worrying about which oil to pick.

I fail to see why this has to be a complex subject on what oil to use in vintage Porsche's. It's not like there are hundreds of 15w-50 / 20w-50 to pick from. It would be easier to simply list every oil in this viscosity with the reduced ZDDP levels and say: "Use anything but these".

I agree on the 1600ppm comment - especially for those who think dumping in a bottle or two of ZDDP additive is a good idea.

cool whip

Time for some apple pie.

FormulaRX

M1 15w50 ftw! That's what I use and will continue to use. Cheap, readily available. No issues...yet

apanossi

What's wrong with Brad Penn 20w50? Been using this for years. Decent zddp content and easy to order online.

Goughary

Nothing wrong w brad penn. it's all I use.

golfnutintib

minor thread - jack

for a warm weather car (993) that is only occasionally driven, and then just for pleasure (say, couple times a month)... does putting in a synthetic oil like v-twin or m1 15w50 allow for significantly longer oil change intervals that dino 20w-50 or semi syn like brad penn?? how long of an interval is advisable?

just curious about this

LexVan

With an oil like V-Twin, change it every 5,000 miles. For low mileage, it should be changed yearly.

cool whip

I am going V twin next oil change.