Changing wheel/tyre sizes

[hamster99]

Most models have options for bigger wheels/tyres to be fitted either at the factory or later.

My question is, as a different rolling diameter will affect the speed calculation, can the wheel/tyre sizes be changed via Lexia?

Rob

[Deano24v]

whilst its true that the wheel size goes up, you should find that the tyre size comes down relative to it so that the rolling radius isnt really affected and if it is the changes arent that great.

a 225/55/17 will turn 754 times in a mile wheras a 245/40/19 will turn 755 times. or at 60 mph on the standard 225/55/17 you would be doing 59.9 mph on the 245/40/19. not really enough to make a difference. changing the tyre sizes though will make a difference.

[hattershaun]

Yes, Lexia has the functionality to change wheel size setting in the car's computer.
I've seen this done on a 2009 C5 Tourer when the owner swapped from 18" to 17" wheels.
I think the information is used by the ESP and ABS systems and maybe the hydractive suspension ECU too.

[Stickyfinger]

Never knew that.....

Maybe if I leave the 17's on the car BUT change them in the Lexia to 19inch low profile I can have a "virtual" bad ride without the expense

[Richard_C]

There is as a handy calculator here:

http://www.wheelcalc.com" onclick="window.open(this.href);return false;