I run mobil 1 10w-30. I was afraid to run anything thicker up her in NewHampshire. I am definalty a proponent of synthetics and have used them for 15 years and the only ill effects are they tend to find a place to leak from if there is a bad gasket or seal. So if you have an oil leak from a gasket its likely to increase the leak. After using it in several turbo cars in the late 80's early 90's with 0 turbo failures even after 150+k even when running more than stock boost on stock turbos. They dissasembled and were clean with minimal wear. That says alot for synthetic oil.

 

Crap Marcus! I was wondering if I should shift up in weight. I just got 2 cases of RP 10W-30 and 1 of the TCW-III. Now I guess I'll see if I can unload 1 locally and get some 20W-50. Maybe 50-50 them and run 15W-40 for a while...

But the TCW-III case has a 1-64 Cristen Powell collectable dragster

 

Not a FD, but same motor more or less, Castrol 20-50

 

Valvoline 20/50 Racing

I change it after every event, so that would mean every 200 miles or so. <VBG>