Outer Limits 4x4 Board

Have been looking at new tyres and have noticed huge difference in tyre diameter in the 31/10.5/15 range.

According to BFGoodrich website
AT's 31/10.5/15 are 797mm
MT 31/10.5/15 are 782mm

My Bridgestone 604's are roughly 750mm.
Was wanting to do rough speedo calculations.
Can anyone who has BFG AT's in the 31's confirm the tyre height for me??
Not that it really matters has got my curiosity going.
Have rung some tyre joints with less than helpful people on the other end considering the amount of $$ I'm about to fork out.

Thanks guys

I wouldnt worry about that variation, just use same brand AND tyre pressure as thet affects it too.
To check speedo borrow a GPS and go for a run along a freeway.

Bazzle