tom, do you think schaeffers full synthetic oil is a good choice for my 04 cobra?

Since you don't have the "run of the mill" Mustang GT, I'd strongly suggest joining a SVT Enthusiasts Online Forum (free to join, of course)...That being said, I DID find an SVT forum with someone asking the exact same question you did...The #1 answer was almost unanimous: Mobil 1 Full Synthetic Oil, but others were mentioned as top picks as well. (I've never heard of Shaeffers either, I'd suggest a well known brand, for certain). Check out this weblink: http://www.svtperformance.com/forums/terminator-talk-229/468722-whats-best-motor-oil-use-my-cobra.html

I've had from New a 1996 S.V.T. Mustang COBRA. I've been Using Mobil 1 Full Synthetic Oil for last16 Year's. I Added Made by FORD Stainless-Steel Header's 12-Year's ago I have 72,000 mile's on it so-far. My Son live's 625 mile's away on Highway I kept track of Gallon's I used Average just about 32, M.P.G.'s.

What ever oil you use,make sure you use a motorcraft oil filter,don't even think about using a Fram filter,not on the Cobra engines anyway.

I use Gold Oil Filter from N.A.P.A. Cost's $ 8.40 Take's 6 Qt.'s Engine oil I use Rotella T6 Synthetic @ Shell Brand @ It cost's $ 4.96 a Qt. Every 15,000 Mile's I have 75,000 mile's on my 1996 S.V.T. Mustang COBRA

1996 was 1st Year they Can with D.O.H.C. @ Double-Over-Head-Cam@ has Aluminum Head's. Engine was Made over in Germany. 400 "Pony's" After I had Stainless Steel Hearder's & Meba Flow Stainless Steel Muffler's. Factory came with High Flow Converter's.