U tuned a customers car with 93 octane he was stock. We r debating wether or not He would see gains by adding 100oct but with out turning up boost. Granted u might not be able to "feel" the gains but r there actaully any gains?

 

No, there would be no gains unless the car is already knocking and not reaching full timing potential. The higher octane itself does not add power. What adds power is the increase in boost, leaning of the AFRs, and increase in timing. If you have no way to improve any of those, then the 100oct is just wasted money.

 

I agree with Warrtalon. Unless the engine knocks there is no gain in using 100 oct.

C16 "may" give you a gain since it is a denser fuel (helps spool turbo) but not enough of a gain for it to be cost effective if there is even a gain.

 

Agreed

In fact using too high an octane in an Evo and you will loose power

Ah - the wonders of Subaru 's adaptive ignition timing where the ecu will advance timing when you give it some race fuel

 

thank u guys for the clear up!