TyreTraders Tyre Calculator is provided to help you work out what differences a tyre upgrade will make to your speedometer.
The values calculated are:-
1:
Sidewall height - this is the height of the tyre from the edge of the rim to the tread.
2:
Wheel revolutions per mile
3:
Ratio - this is the percentage difference between the circumferences of the tyres.
4:
Radius - this is the radius of the wheel and tyre combination i.e. the distance from
the centre of the wheel to the edge of the tyre
5:
Wheelarch difference - this is the extra amount of wheelarch space that
the new wheels take up; it can be useful to work this out if you are worried
about the tyres rubbing the wheelarch. If the value is negative, then there is
more wheelarch clearance. Also note that it is only working out
height differences, not how much extra the a different wheel will stick in/out.
6:
Speed differences - " how will it affect my speedo?" Please use the tyre calculator above!
Please remember that these are only
theoretical values, and that in usage the values you may see can vary due to
tyre wear, tyre pressure, tyre make, etc. Check that the new tyre size
is currently in production.