TimC

iTrader: (1)

I think 620 is the diameter in mm

youngben

iTrader: (2)

so they will be 200/62/16's? where as mine are 194/40/16?

Mike Rainbird

iTrader: (3)

No, you would have to work out the profile, as race tyres are done differently.

Race tyres will be the width x diameter. Road tyres are width x aspect ratio (in your example 40% of 195 would be 78mm, which is the sidewall height).

You would have to calculate the sidewall height of the 620mm tyre like this:
16 x 25.4mm = 406.4mm (the diameter of the wheel).

Subtract the wheel diameter from the tyre diameter to get the total tyre height: 620mm - 406.4mm = 213.6 / 2 = 106.8mm sidewall height.

As an aspect ratio that would work out as 200/53 x 16.

Chip

iTrader: (3)

Mike's along the right lines.

The tread on a 200 width tyre is more like a 195 of tread though, so the nearest direct equivalent is a 195/55/16, which comes in at 621mm overall diameter.

youngben

iTrader: (2)

thankyou lads big help that! going to treat myself to some now i know they fit