Can 91 Octane Fuel be Ran with Superchips Tune that Calls for 87 Octane

Published 12/21/2021

Question:

Can you run 91 octane with the mileage XS tune or is it only calibrated for 87 octane??

asked by: Carson

Expert Reply:

You can run higher octane than what a tune requires but you can't do the opposite. So if you have an 87 octane tune loaded you'd have no issue running 91 octane. But if you had an 91 octane tune and ran 87 you'd cause damage most likely due to detonation.

Basically the higher the octane the more timing you can run before detonation which increases power. If you run too much timing with lower octane fuel though you run into problems. But having more octane than needed for the timing that is being ran does not hurt anything aside from costing you more per gallon.

expert reply by: Jameson C