Ronald

Shell Ultra-Performance 0W40, if it's good for Ferrari F1 then it must be good for my S2000.

AVXs2000

I heard the Endless R-505 and Blitz Power Performanceoil zero that are selling in Japan is always pretty good for the F20c.

Need4Spd

Mobil 1.

Radster

Castrol 10-30 works fine for me. It's inexpensive, and I change my oil every 2,500 miles anyway. IMO synthetics aren't worth the x-tra $$$......

Need4Spd

With your frequent changes at 2,500, I'm sure it's fine. But note that the S2K's redline is what? about 9,000 RPM? Lots of shearing forces. Synthetics are built from the ground up, molecule by molecule and have nice strong evenly sized chains. They hold up much better under shearing forces than dinosaur juice.

Freakaccident

I use SuperFlo Synthetic 10w30. Its the only oil I have tried that gets rid of lifter tick in my POS 3kgt.
Aaron

Takashi KazuMori

I'm another owner that oil changes every 2,500KMs. Why? Because I always push the car to it's limits until the engine oil peaks boiling point. Maybe it might seem to be an un-necessary type of maintenance to some but for me it's just great. I don't mind paying the bit of extra and having a peace of mind that at least I'm doing my part in keeping the car well maintained to the best of my ability.

Need4Spd

Takashi, if you often push the boiling point, what you are doing is prudent. The factory recommended mileage between changes is based on "average" driving conditions, but the manual itself states that you should change more often under "severe" conditions. The driving you describe is severe.

S2OOO

Catsrol Syntec here.