What does everyone run in their quads? I'm not interested in blown w/alcohol injected monsters, but I always run 92 (premium) in my 400EX, but I can't really tell a diff. in the 87 octane. What about 110 octane, or maybe using 92 and an octane booster?

 

Just run what the manual tells you as long as it is stock. Going beyond that is a waste of money. Higher octane does not mean more power, just a higher resistance to pre-ignition. If you run a high comp. piston or other internal mods, run what your engine builder or parts supplier recomends. Simple bolt-ons like a pipe, air filter, and jet kit do not require a jump in octane rating.

 

totally true.unless your motor is built ,there is no use in spending $4 bucks or more a gallon for race fuel.about the only thing you would notice on a stock motor or even a mildly built one is that they tend to warm up a little faster and race fuel actually will slow your throttle responce.believe it or not.pump gas is more volatile and burns way faster then race fuel.and i highly recommend the 92 or 93 octane pump gas for normal use .i don't advice running the lower grade stuff though.you get run into rough running and idling not to mention preignition and detonation.

 

The 400EX owners manual specifies 92 octane. Calif premium pump gas is 91. To get a little extra octane (to get over the 92 ocatane minimum), I mix 108 ocatane race gas 1:5 with pump gas, for an average octane of 94.4. Going real high with stock compression is overkill.

 

Good info to know. Thanks.