a handy tyre calculator

[adamh]

java script calc for comparison of tyre sizing from one size to the next with visual display and other data.. handy.
http://www.miata.net/garage/tirecalc.html

[Paul Woods]

this is very handy,i use it myself all the time...i'll sticky it so it doesnt dissapear over time.

[stevenb]

I use the older version. which is linked on that page.
still deffo worth a sticky. 8)

[adamh]

dumb a** me didnt see it had been brought upbefore on apr 4th by paul!.. the wonders of stickies ..

[SH1FTY]

Ok, so me being Shropshire born, Shropshire bred, strong in the arm, weak (ish) in the head...

Does this mean that with my current wheels and tyre's my speedo will be way out? UK Rev 5 i think has 15's as standard but i'm not sure on Rev 5 stock tyre sizes... Currently i have 215/40/17 Front and 225/45/17 Rear.

[snowtigger]

Same sizes as me and my speedo reads bang on at 70mph and on the tomtom 70mph, all depends if the rolling circumference changes find out stock wheels and tyres and see if your circumference is the same.

You could be 5 mph either way.

[SH1FTY]

Same sizes as me and my speedo reads bang on at 70mph and on the tomtom 70mph, all depends if the rolling circumference changes find out stock wheels and tyres and see if your circumference is the same.

You could be 5 mph either way.

Cool, thanks for the reply! I've checked against my tomtom too and it tends to be pretty much bang on bar 1-2mph at various speeds... My BMW which was totally standard always read a different speed 7-9mph out to what my satnav told me so i'm not sure how that works... Oh well :)

[snowtigger]

normal speedos are about 10 percent out either way, only cop cars have them calibrated spot on some just have or used to have extra speedos.