And buy the 93 octane as well. It is a well known fact that most people will get better mpg's w/ 93 over 87, tuner or no tuner. Like i.ride.suzuki, I was getting 12.5 to 13 mpg's on 87 and when I switched to 93, I noticed an instant improvement in my milage, around 15 mpg. I think with the 93 tune you get better response off the line when going from a stop as well.. Of course, that means it's more fun to take off from a stop, and THAT will decrease your mileage. I guess it depends on what you can afford, better mileage, or cheap gas! Btw, I've been filling up with 93 at $2.59 a gallon for the last week. Wish I knew why other gas stations are so much higher in price (besides greed), by about 50 cents more a gallon, and that's only 15 minutes down the road from where I've been filling up, same kind of gas station too!

 

I do get better mileage out of the 91 performance tune. I also can't stand driving it with any other tune. Haha.