Originally Posted by Gazza

Hi Paul,

You can check the size of the new tyres with the original fitment with the following link...
Tire size calculator

It's a tyre/wheel calculator.....

I'm Getting some 20" tomorrow - 8.5" on the front with 245/35 tyres
and 10" on the rear with 275/30 tyres.... Which is a pretty standard/common
combination.... I was gonna go to 285 on the rear but a 10mm increase in width made the price jump too high as they are not as common as the 275..
The rule is that the rolling diameter should be within 3% or less of the original Specs....(stock wheels/tyres) Otherwise it throws out your Speedo & Odometer too much.....

Gary...