Real tyre sizes..
 

I was running the tape measure over the TJ the other day doing some measurements after a recent 3.5" suspension lift which made my 33x12.5R15 MTRs look small, I put the tape over the tyres only to be shocked by a overall diameter of just 31.25". Whats the go there.

Is there a 33" tyre that is actually a 33".

Simex. Most tyres though are like that. i think they round it up in mm then round up again when convert it to inches.

Rim size, backspacing and tyre wear are also factors - correct me if i'm wrong but that same tyre on a 15x7 would measure taller... and on a 15x10 it will measure even smaller

Tyre measurements are taken diagonally ;-)

So I was always told (?), from the bottom outer edge to the top inner edge.
Its the only way some brand of tyres actually come close to their reported measurements.

Like a TV screen - Corner to Corner ?

I guess the only solution is to have two sets of wheels and tyres perhaps, a set of 33"MTRs or similar on alloys for general touring/road/beach use and a set of 33x11.5 (true 33" dia) Simex JTs on steelies when the heavy offroad play happens or when I try to keep up with the BIG boys in their Landcruisers/Patrols/Rovers.

But a tyres round. and the diameter is the same all around? :%

even ify ou flat spot them??? :p