Using higher Octane then mapped

GBAILEY472 · Oct 28, 2009, 02:22 PM

Will it make a difference or not ? example my mapping is set @ 94oct , if I fill the tank with 100 or 110, will I make more HP or is it useless ? will it result in knocking
what the worst that can happen ?

Please explan your answer..
Thanks

NickieBlaine · Oct 28, 2009, 02:24 PM

If you use a higher octane, it wont do anything unless you add more boost, more timing, etc. If your tuned for 94, and run higher, it wont hurt, but its just a waste of money.

Murf · Oct 28, 2009, 02:26 PM

will do nothing for you..actually make you a little slower.
why you are not burning the fuel completly.
if tuned for 93 and you have knock adding 100 will up the oct. level and supress knock or help supress.

GBAILEY472 · Oct 28, 2009, 02:30 PM

No, I was just curious as to leveling down the fuel means less boost to prevent knock but I wasnt sure what the results were on Higher fuel levels

SoCal Rally · Oct 31, 2009, 11:02 AM

Won't make any extra power (unless your car was pulling timing because your car was knocking already due to too aggressive settings).

Will increase resistance to knocking due to higher octane. Some people doing road racing track events down in Southern California (or other hot states like NV and AZ) will sometimes add a couple of gallons of 100 octane unleaded to help increase knock resistance with this since track temps in the summer can be super hot, and often the car may not have been tuned with the same extended load and temps seen during road racing.

Be careful with 110 octane, since most of those are leaded (as opposed to unleaded). Your engine probably won't care, but your O2 sensor will get fouled pretty quickly.