tyres

[wilburwilde]

Hi all,
Does anyone know know the overall diameter of a 6.40 x 13inch tyre.

So a 185/80r13 then equal a 6.40 x 13 roughly as i have read somewhere before??

The reason i'm asking is cause at 80kph (50mph) the poor little engine seems to be reving it guts out and = not getting to far. It currently has 185/75 r13's at the moment, and i'm trying to decide on a tyre choice for early next year. I don't want change the diff ratio. I know it well never be a speeder but just want a bit more than what i've got if its there to be had.

Thanks for your help.

Will

[sgo]

This site should answer your questions?

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

[wilburwilde]

Awsome, Thanks heaps SGO.

A very handy convertor.

Will

[Fc1958]

Isn't there a diff ratio you change to that gives longer legs using a 185/80R13 and lets the engine run lower revs?

[wilburwilde]

Mabey so but i'd rather not change diffs, checked some manufacturers and dealers eg typower etc local to me and none list any close to size. How many people run the 6.40 x 13r from http://www.antiquetyres.com.au/taxonomy/term/324 and what do you think of them to use??

Will