Motorcraft 5w20. I ran M1 in my '01.

you joking? that car(ls1 trans am 5.7L) calls for about 5.5qts in that motor.....aftermarket oil pan or anything? i dont know if throwing a full extra quart in there is going to be a good idea.

if thats the rule of thumb does a honda s2000 take 9 qts in its little 4 banger?

I run a full 6 quarts in my LS1's, but I run a deeper filter on the Formula.

You can run 5w30 in the Mustang.

I use Royal Purple.

AMSOIL is my choice. The European Formula 5w~40 to be exact.

The 5w-40 European motor oil is supposed to last 25,000 miles and retails for $6.85 per quart, $81.00 for a case of 12.

Compare that to the cost of replacing Mobil, Castrol at the recommended drain intervals and the AMSOIL comes out on top with value not to mention wear resistance and breakdown.

All you would have to do is change the filter @ 7k miles and rock on for another 7k. Then change the oil even though it's still got 10,000 miles left on it.

They also have some abuse tests in this brochure that shows the results between AMSOIL, Mobil, Royal Purple, Castrol.

I know they did the tests, but the figures are "overwhelming" in favor of AMSOIL
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Hmmm...I use half of what you do! I spin around 6k and use 3 quarts. All that extra oil is slowing your chevy down.

Actually, running low oil on an LS1 is a recipe for disaster. Even 1.5 qts low with a hard launch is enough to uncover the pickup and see 0psi on the gauge. :eek2: You gotta keep those suckers full of oil. They have a nice windage tray on them though, and the sump is big enough to keep the oil off the crank, even a bit overfilled.

How nice can the windage tray be if you can uncover the pickup that easily?

Mobil 1 5w20

Royal Purple here.