My buddy is wanting to run his stock crx si motor at the track this weekend. What kind of fuel can he safely burn in the car?? All he has is headers and exhaust. Would this change for a B series motor? How high of an octane can a stock B series take? Thanks

 

IMO he doesn't need a higher octane. Higher ocatne doesn't increase power it just increases the resistance to detonation. There is really no reason to run higher octane unless you are running high compression, forced induction/nitrous. If you advance the timing just run 93 octane and it will be fine. The motors will run with 100+ unleaded octane but like I said there is no point on a relatively stock engine.