Originally Posted By: OVERKILL
Originally Posted By: Stewie
Originally Posted By: seanf
IMO if you can't feel a difference the only way is to data log knock sensor data and timing pull using regular and premium fuel and see if there is a change, I run premium in all of our Audi's most of the year, the 2 that don't have REVO performance software get 87 octane in the winter and I don't notice any performance difference, just a difference with worse mileage as most of our 91 gas has no ethanol and all of the 87 does have it so I've since decided to just run everything on premium.
Expensive though
My brother's audi just runs regular
Premium here is bout $.30 more per LITRE not gallon
Does your brother's Audi allow for regular (87)? Yes, gas is expensive. A cracked piston or lifted ring land is a lot more expensive though.
My bimmer has 11:1 compression and calls for 91 octane. So it gets 91 octane. I knew that getting into the car. The Charger allows for 87 or 89, both are acceptable.
Run what the TSX manual lists as acceptable. If that includes 87, you are fine. However, if it specifically states to run 91, run 91.
Otherwise, you are just gambling that the knock sensor is sensitive and responsive enough to stop this from happening:
Oh yeah my brother runs 87 and for gf's TSX it says minimum of 87 octanes we good