New for new that's 15mm difference. More than recommended tolerance.
how do you work that out?
15" = 38.10cm
16" = 40.64cm so only 12.5mm difference not counting the sidewall depth
take into account that the new sidewall is 10mm smaller than his previous sidewall that gives a total diameter difference on 2.5mm....
It's not 10mm smaller. Wall profile is a percentage of the width.
New sidewall isn't 10mm smaller though. The middle figure is not mm, it is the aspect ratio i.e. percentage so a 165/65 14 tyre is 65% of 165.
There won't be a great deal of difference in speed but there are tolerances that should be adhered to. The actual speed difference is only about 1mph at 30 and 2mph at 70 but if you had a bump, it could be picked up by an assessor and insurance could be voided.
Worked it out. 19.9mm difference.
Between 15' with 185/55 and 14' with 195/65
Edit. Just realised he said 165. Waste of maths that was.
So what does this all mean? Lol? Will
it bugger the speedo? Or?