Castrol GTX 20w50 $15.27 5 qt Walmart
 

Stumbled across a great deal . What I use in my air cooled 911s and motorcycles - Castrol 20w50. Walmart has it on special for $15.27 for a 5 quart container. If you buy 4 you are over the $50 requirement for free shipping. You don't even have to leave the house!

Have you researched Castrol's ZDDP in relation to air cooled cars? Most folks don't recommend it.

No I have not. But I have been using Castrol 20w50 in all my air cooled vehicles since way back. Never heard of ZDDP. I go on experience. It has served me well. First 911 bought in 1980. I am interested in hearing what you have heard about ZDDP though.

Pour yourself a stiff drink...
http://forums.pelicanparts.com/porsche-911-technical-forum/367300-ultimate-motor-oil-thread-why-we-hate-cj4-sm-oils.html

In the '80s and '90s, GTX along with Kendall GT was pretty much all I used in my VWs, MGs, Triumphs, etc. However, I'm pretty sure Castrol changed the formula. In my 930 I ran Brad Penn 20w-50 and eventually switched to Mobil 1 V-Twin 20w-50. In my 993, I also run V-Twin. For my next oil change in the 993, I'll be switching to Joe Gibbs Driven DT50 (15w-50).

Castrol 20W-50 was all I ever used in my old Bug and also when I first started driving a 911. It had a great reputation for decades. It has fallen out of favor for a reason, however.

Go with sand_man's suggestions.

Yeah, if you were a 'car guy' back in the day, Castrol 20w-50 was IT.
Haven't used it for quite some time in any of the cool cars because I don't feel like the formula can be trusted anymore.

I have some oldskool cans and dealer clock though. :)

http://i18.photobucket.com/albums/b1...e/DSC00267.jpg

http://i18.photobucket.com/albums/b1...e/DSC08039.jpg

^^^Luv that ol' skool can!!!! I remember those!