I want to fill up the wheel openings with a larger that stock tire/wheel combo on my 02 Z convertible. If the diameter of the tires on the rear are somewhat larger than stock, does this affect anything else other than speedometer like engine controls? I asked this in another thread that appears to be closed & I probably dodn't make myself clear. I mentioned larger wheels but not larger tires. I do want larger tires. Thanks.

 

You can put larger tires on, and correct the PCM tire size to show the correct speed. There are tables in the PCM that require the correct vehicle speed. Some people seem to feel that different front and rear tire diameters will affect the ABS system, but I have not found that to be true, and I run tires as large as 28" on the back. I'm not sure how it would affect the traction control system, if you have that.

When you run a larger diameter tire in the rear, you are raising the rear of the car 1/2 the difference in diameter, giving the body a definitie rake. Larger diameter rear tires also have the same affect as going to a lower numerical rear axle ratio, and require more energy to bring them up to speed.