Overall diameter of wheels+tyres

[pinklady]

hi all.

i know that the overall diamater of a wheels+tyres for 55/R15, 45/R16 and 40/R17 are the same.

anyone know if 35/R18 is bigger or the same?

[95_CVC]

well im having trouble wit my wheels. i bought new rimz they are 35/r18 and most places said they wont fit them for me cos the rolling diameter bigger than stock and they dont wanna do illegal stuff. But i found someone whos doing it 2moro ;) So i'd say bigger.

[tinkerbell]

try using this calculator:

http://www.miata.net/garage/tirecalc.html

looks like 35's would be right for 18's (slightly bigger by 0.9%)

[madgrk]

try using this calculator:

http://www.miata.net/garage/tirecalc.html

looks like 35's would be right for 18's (slightly bigger by 0.9%)

Depending on the width, they don't neccessarily need to have a large rolling diameter. Try running a 205 or something like that and see how you go.

I'd do the calculations for you, but have no idea what the tyre you're comparing against is (size wise)

Theo..

[Domokun SPL]

I use this website.

http://www.1010tires.com/TireSizeCalculator.asp

I find it good, works for me perfectly. I managed to remove compliance tyres and put on original diameter tyres (not same size, but same rolling) and that brought my speedo back into close close to accurate.

[pinklady]

thanks everyone for theh elp wth the links, they're all very useful. thanks :)