i have an 02 honda 300es and i have jet kit ,K and N filter, header and FMF muffler. i was wonder wjat octane gas i should use all the time . i also want to know if i can only use like 87-89 is it ok to use like 93 sometimes let me know thank
Alex

 

man with that power house, you need to run 110 octane (race gas)!! lol j/k your fine for running 89, we run 92 but, it don't matter

kc

 

thanks ill continue to run 89 then thanks alot
Alex

 

The only thing that determine's what octane you have to run is increased cylinder pressure (supercharger,turbo,n2o,and compression) if your engine is naturally aspirated you should be ok with the following
1.10 to 1 compression and under cheapest pump gas you can find.
2.10.5 to 1 - 11.5 to 1 compression use premium 92 octane (if your air cooled you may want to use race gas increased temp increase's cylinder pressure and can cause detonation)
3.12 to 1 - up use race gas.

Basically the higher cylinder pressure's the higher the octane for slower burning to keep it from detonating.
Turbo's and supercharger's are going to be low compression engine's with compressed air adding to it which increase's cylinder pressure there for you need higher octane
N2o depend's on how much n2o you are using.

We drag race big displacement drag car's we have a 70 Camaro with a 706" big block pushing close to 15 to 1 compression and we use Sunoco purple 118 octane leaded gas and then add 3 n2o fogger's total horse power close to 1900hp
Friend has a 69 Camaro with a 380ci small block fuel injected twin turbo running 8.5 to 1 compression but adding 32-38lbs of boost and they also use the Sunoco purple 118 octane making close to 1900hp also