Hi everyone, been going through this forum for a couple days. I'm thinking of picking up an M35x 2006, soon. I live in the Chicago area, so I must have the X model and I know I'll have to swap out the tires if the stock ones are on. My biggest concern is gas mileage. I currently own a 2006 Grand Prix GXP, which has a V8. I drive 60 miles a day on the highway and if you know chicago, rush hour traffic isn't exactly smooth. In my V8, I average about 18mpg every week if that gives you any indication of my driving style. I have a heavy foot, but I stay away from fast starts and stops whenever possible. I'm hoping to get 20 - 22 mpg, think it's possible in an M35x with 75% highway, keeping in mind, a lot of that highway is stop and go. Thanks everyone.