Tune, CAI, DashHawk, and Heat Soak Reduction Kit on order (probably a kitchen sink in there somewhere as well).

Anyway, most premium around here is 91. Got a couple BP's at 93. Ordered tune for 91. So, if tuned for 91, what happens if I run 93? And on the other side of the coin, if I got tuned for 93, what would happen if I ran 91?


Thanx for the info!

If you tune for 93 and use 91 you will ping and detonate.

Better to tune for 91 since staion gas is not always the same.

Actual Octang rating is lower than posted alot of times.

From what I have read from VMS, that is not true. The ECM will adjust for the lower octane and not let the car ping and detonate, however, your mileage might suffer. Don't think you will have a problem on mileage between 93 and 91. BUT... if you run 87, the timing will retard to the point that your mileage will suffer. The main reason for a VMS tune for performance and mileage is that the tune leans out the engine and also maximizes the timing for optimum performance and fuel usage. IE: you get the best of both worlds with the tune, better performance and better mileage.!!!!!!


Of course you could worry about Octang and alot of staion gas..... Personally, I trust people who know how to spell and are willing to proof their comments....
RRM

If you tune for 93 and use 91 you will ping and detonate.

Better to tune for 91 since staion gas is not always the same.

Actual Octang rating is lower than posted alot of times.

Fairly sure that it is a misdemeanor to have a pump that puts out an octane below what the sticker says....

carry a bottle of octane booster in your boot, oaah that is trunk, in case you have to fill with 91 :)

Tune, CAI, DashHawk, and Heat Soak Reduction Kit on order (probably a kitchen sink in there somewhere as well).

Anyway, most premium around here is 91. Got a couple BP's at 93. Ordered tune for 91. So, if tuned for 91, what happens if I run 93? And on the other side of the coin, if I got tuned for 93, what would happen if I ran 91?


Thanx for the info!

Won't hurt a thing, you could even run 87. I asked VMS this very question when I ordered and the only thing that will suffer is mileage.

--Mike

Any difference in performance on 91 vs 93 tune?

What about MPG? does 93 get 1 mpg better than 91?