21-05-2021, 03:11 PM
Alan has allready hinted at the answer.
The 'true circumference' ( lets call it that so its easy to understand) is effected by a number of things, not least tyre construction and pressure.
There are 2 easy ways to get a pretty good answer.
1. Park the car on a hard surface and measure from the surface to the centre of the wheel. This radius will give you a pretty close answer.
2. Mark the tyre in pencil. Mark 2 lines on the ground (also in pencil) at start and stop for one turn. This will give spot on answer assuming you can mark and measure accuratley.
A tyre with a larger at rest diameter will not neccassarily give a bigger number. Though as a generalism you might expect it would, and probably does.
The 'true circumference' ( lets call it that so its easy to understand) is effected by a number of things, not least tyre construction and pressure.
There are 2 easy ways to get a pretty good answer.
1. Park the car on a hard surface and measure from the surface to the centre of the wheel. This radius will give you a pretty close answer.
2. Mark the tyre in pencil. Mark 2 lines on the ground (also in pencil) at start and stop for one turn. This will give spot on answer assuming you can mark and measure accuratley.
A tyre with a larger at rest diameter will not neccassarily give a bigger number. Though as a generalism you might expect it would, and probably does.