Just bought my first Mazda, a CX-9. So far, I love it, but one thing I wasn't counting on was the 20" wheels. Any opinions about 18" vs 20" - ride, performance, MPG?

I expected


If 18's fit, you will gain some MPG and ride softness/quietness over the others. As it's an SUV, i'd be surprised if 18's didn't fit as usually the only thing standing in the way of smaller diameter wheels is brakes.

Thanks.
My other car has the yellow handlebars and streamers.

Depends on how quality of a wheel you get and if you match the outside diameter of the existing set up. Essentially, if you match the rotating weight of the current wheel set up, you will get the same mpg. If you make it lighter, then you might save mpg. If you change the diameter of the wheel/tire combo, your speedo could be off some and might affect the estimation of mpg.

If you get more sidewall (extra sidewall to make up for smaller wheel), you will have a more compliant ride because there is more sidewall to flex and absorb bumps (like road joints).