hey guys so I've been building a motor to slap a turbo on later in the future. I've never had a turbo car before so I've been doing as much research as I can. but I had a simple question. why is everyone tuning on 91 octane? since the car requires 93 if it's stock. is it bad for the turbo or something? I know the higher octane rating the more I can compress it without it pre igniting on me so if it's not bad for the system i'll probably run 93 octane. but im just curious as to the side effects versus 91 octane

 

they run 91 octane because its the highest available at the pump. If you have 93 at the pump consider yourself lucky and enjoy the extra little bit you get with it.


lower octane = more uncontrollable combustion so running lower grade octane will actually hurt your car.

 

yea I knew higher octane was better. we do have 93 at every pump and I actually work at a shop that sells race fuel 112 octane I believe. and e85 so I didn't realize 93 wasn't available like that in other areas

 

I think it is geographical....we have 93 everywhere...but no e85...which sounds like the route to go.

 

The OEM F20/22 requires 91 minimum, not 93. 91 is the lowest available of the high octane fuels across the country, so it would make sense the car was tuned for this from the factory. We have 92 in WA.

 

we run 91 octane because here in california 91 octane is the highest grade of gas there is on the pump. Yes 93 octane is much better and typically on turbo s2000's and evo's normally 93 octane is good for about 50whp then 91 octane.

 

93 is the norm for pumps around here.


Better question is, if you've never owned a turbo car before, why are you building an engine? Do you plan to make more than 700whp?

 

I have 93 everywhere but unfortunately no e85. Really wish there was!

 

Lol I smell a troll too..