From: Barry Lovelock
Date: 26/02/99
Time: 15:13:14
Remote Name: 212.250.195.135
The proper rolling diameter should be 25 inches with a 5.25 diff. This is derived from 17 inch wheels and 4.00 x 17 tyres (17 + 2x4), which was the English standard fitment. The export 16 inch wheels should have tyres of a size fitted to arrive at the same diameter, with the same gearing - overgear and it won't pull in top gear - better to go the other way. So I would say 4.5" section tyres were correct. This assumes in all cases the aspect ratio of the tyres is 100%, as it is with pre-war ones. If they are modern they will be 80 %, or Heaven forbid, 70% or lower and you will have to compensate. Too wide front tyres destroy the steering feel anyway.