Originally Posted By: FlyPenFly
No brainer... I wouldn't use M1 unless you're using their racing versions.
The AP1 S2k revs to around 9k IIRC. I would only use an ester Redline or similar level of oil in as narrow a range as possible like a 10w30.
Really, every S2000 came from the factory with 10/30 dino oil. My old R6 reved to 15,500 and did that on dino oil. If his AP1 doesn't use a lot of oil M1 will be just fine. But if his S uses a lot of oil at the track then he should move to a different brand of oil to see if he can find one that will stay in his engine. I know too many that track their S2000 and run 15/40 dino for the extra boundary layer strength that that oil gives on high temp track days.
ROD