[Flavor 987S]

Most of the 964 guys I know are running the Brad Penn. This is also a highly recommended oil by Charles Navarro.

Here is an excerpt from his web site:

"Which motor oil do I (Charles Navarro) use in my aircooled Porsche?
Although there are many excellent motor oils out there, considering the wide array of oils I have access to, I currently am using Brad Penn 20w50 API SJ for the summer and winter months in my aircooled Porsche since it never sees sub-freezing starts. The Brad Penn Penn Grade 1 Racing oil is the same "green" oil everyone was familiar with back when Kendall GT was the best motor oil money can buy, as both the original and this newer product both come from the same facility using genuine Pennsylvania crude. These oils are proven to protect cams, rockers, lifters, and all valve train components as well as provide superior rod bearing life because of their very high HTHS viscosities AND low levels of individual detergents to net a high level of detergency with the use of Ca, Mg, and Na synergistically. Just ask anyone about the "green" Kendall oil from decades past and you'll know why we like it so much. Likewise for winter service, we run Brad Penn 10w40 API SJ.

Another great oil, if not a bit expensive for a non-synthetic oil is Swepco 306 15w40, which comes highly recommended by Jerry Woods, a very well-respected and experienced Porsche engine builder, and is another oil we regularly use.

Both the Brad Penn and Swepco oils are highly refined paraffin base stocks, and I feel they are excellent choices for aircooled engines, providing better protection and used oil analysis wear results than most fully synthetic oils.

In my two newer vehicles, both of which are Volkswagens, they require a VW 505.01 specification motor oil, and I use Motul 5w40 505.01 specific, which is an API SJ rated semi-synthetic. It has since been superceded by a new We have also used Motul's 300V, which is a group 5 full-synthetic ester oil formulated like Brad Penn (in regards to additives), Motul 8100 X-Cess, and Motul Specific 502 (which now meets 505.01 requirements) with equal results.

Very important in my consideration of any of these oils are that they have the proper balance of Zn and P as well as level of detergency. Oils with high detergency need equally high levels of anti-wear additives as well as those oils using Ca-based detergents also need more Zn and P that those oils that use Mg and/or Na detergents. Brad Penn, Motul 300V, and even Mobil 1's motorcycle oils all use lower levels of Ca detergents and the less aggressive (lower wear) Mg and Na-based detergents.

I do not recommend using ZDDP boosters.

What viscosity motor oil should I use in my Porsche?
Porsche nicely answered this one for us (from '84 911 owners manual). You can use a 20w50 year round, even with cold starts to 20F, which covers the majority of Porsche owners. I might add, if your Porsche is also your daily driver and you see repeated sub freezing (32F) starts, it wouldn't hurt to use a 15w40 instead. The other recommendation frequently given by engine builders is that a 15w40 can be run up to 90F ambient air temperature and at higher temperatures, a 20w50 should be used.

We have also tested the Brad Penn 20w50 versus a 50/50 blend of the Brad Penn 0w30 and 20w50, which yields a 10w40 viscosity, with near identical low wear levels, regardless of viscosity. The used oil analysis for the 10w40 can be viewed in PDF here as well as for the 20w50 by clicking here. Both sets of tests were conducted on a 1991 c4 cab with a 3.6 liter normally aspirated 964 engine with approximately 60,000 original miles."

Here is the full Q&A (this is not new news, we have discussed this in the past here):

http://www.lnengineering.com/oil.html