I've logged about 2,400 miles since I installed my base SOS SC since mid-August of last year or 9 months ago. I'm running Amsoil 10W-40 and unfortunately, always forget to collect some sample oil from my S2000 before it's too late to send to Blackstone for analysis (I've done it with my other cars though). Hopefully this time I will remember to collect a sample, but was curious when do you think I should change it?

 

You need to drive that car more man

I change my oil about every 2.5-3k, I run Syn as well. I notice the quality declines pretty rapidly if I push it much beyond this. You could likely let it go another 1k with your set up. I run water/meth as you know, it puts a bit more contaminants in the oil.

 

Word to yo Junkeh!

Junkey is right, drive moar and IMO dont go beyond 3k with FI. Im a freak and change every 2-2.5k, but rather safe than sorry and I want my motor to last, its cheap insurance. AMSOIL FTMFW!