There are numerous threads on the web about this question but I cannot find any logical answer. My '68 1500 owners manual lists stock tyre size as 5.60 x 15 (cross or bias ply) or 155SR x 15 radials as an option. The crossply has a diameter of 655mm and the radial a diam of 630mm. This is a difference of 25mm (around 1 inch). I am puzzled that precise German engineers wouldn't be concerned about the difference 25mm diam would make to the speedo and the gearing or am I missing something here? (VicRoads would be concerned!)
Cheers........Wayne
hulbyw ·