From what I've read here on the forum, the rear tires need to be taller than the front (larger diameter/circumference). If the rear tires are the same height or smaller than the front, the car perceives this as wheel spin and in turn activates the traction control.
Some people have claimed to have no issues with all four tires the same on the car but I've also read that someone had issues above 80 mph with the aftermarket tires sizes they chose, traction control engaging. This thread...http://www.gencoupe.com/wheels-tires-brakes/45450-traction-control-wtf.html whether it was proven to be the tires or not I can't say...but in this person's case the difference front to rear was 0.8% .
Using the calculator I provided in the link below, (assuming it works correctly) and using the stock 19" tires sizes (F 225/40/19 - R 245/40/19), there is a 2.4% difference between the front and rear. With the stock 18" tires (F 225/45/18 - R 245/45/18) there 2.7% difference. So I think it's safe to say that anywhere in between you should be ok.
Calculator (bottom of page in the link)...Tire size calculator
Some people have claimed to have no issues with all four tires the same on the car but I've also read that someone had issues above 80 mph with the aftermarket tires sizes they chose, traction control engaging. This thread...http://www.gencoupe.com/wheels-tires-brakes/45450-traction-control-wtf.html whether it was proven to be the tires or not I can't say...but in this person's case the difference front to rear was 0.8% .
Using the calculator I provided in the link below, (assuming it works correctly) and using the stock 19" tires sizes (F 225/40/19 - R 245/40/19), there is a 2.4% difference between the front and rear. With the stock 18" tires (F 225/45/18 - R 245/45/18) there 2.7% difference. So I think it's safe to say that anywhere in between you should be ok.
Calculator (bottom of page in the link)...Tire size calculator
