Sunoco Racing Fuels

SE

This is incorrect.

VQ37 can run higher octane fuels without a tune. 91 octane is just the MINIMUM recommended octane. You can get more power out of a slightly higher octane. The ECU will automatically adjust the timing/fuel trim curve for the best power/economy to a certain extent, meaning that since 91 is the highest grade premium found in some states, use of a higher octane fuel will yield small power gains and trigger the ECU to adjust timing as a result.

However, I wouldn't recommend running higher octane (92+) all the time, since better mods can be purchased for the same price as a few fill-ups with high grade premium.

I also wouldn't recommend running higher than 96 octane or a 91/100 mix, since the ECU will most likely not be able to adjust itself to the 100 octane race gas, and 100 octane race gas is damn expensive. Just make sure it's unleaded unless you want to kiss your O2 sensors goodbye.

Scott @ RA

^^ +1 Mostly true (for the most part)....
Its not as if the ECU will actually advance the timing to generate more power if there is higher octane fuel (that is a little misleading). The ECU will however detect slight detonation and retard timing as needed to an extent (which is caused by heat and other variables, but mostly caused when octane is too low).

OP, basically what others are telling you here in a nut shell is higher octane other than 91/94 is pretty much a waste of money for you at this point. You will not see any noticeable gains, or gains at all using higher octane fuel. Also, stay away from any extended use of leaded fuels, it will eventually burn out your 02 sensors.

Vegitto-kun

The sticker on my car tells me to use 98 octane so I follow it.

Only problem with the GT-R is that it tells you to use 100 which no gas station has here.