level 3 canned tune with 89 or 87 octane?
 

Can i run level 3 on either 87 or 89 octane by just lowering the timing .5 points for every octane number i go down?

i dont want to spend the 91 octane prices if i dont have to...

i'm not racing or anything, just a highway commute... so i dont need power, just savings

Shorse, Corey answered this a while back in one of her posts. I can't think of a good "search string" to use for it, so I'll just tell you what I remember.

Basically, don't do it! There are other factors in the Level 3 tune besides timing. If your engine is under load, even with the timing reduced, using Level 3 will put stress on your engine that could be harmful. Only use Level 3 if you are using high octane gas.

Your vehicle will probably run better overall anyway (more power) if you use a tune that matches the fuel octane you are using.

- Jack

very good to know.... i need to fill up tomarrow... i will try the 91, see if i can make my money back by getting more mileage..

thanks for the quick responses!