Thread: 265/70/16s on a SII Disco

i beleive the 245 stands for width of the tred in mm, but apparently not always accurate, the 75 is a percentage or something of the width which is the sidewall height. I think that is how it works.

Originally Posted by ak

245/75 on 16" rims, the 75 stands for diameter? So with a slightly higher diameter ( from 70 to 75 ) does it throw the speedo out and lose some power. Or am I competely confused?

No not confused, yes it does, throws the speedo out by 4% and yes sucks some power from the car, to bring mine back to standard power so to speak i had it chipped/ECU remapped.

If you don't tow it's not a big issue but we tow a heavy camper so the chip was a necessity.

Baz.

Originally Posted by ak

245/75 on 16" rims, the 75 stands for diameter? So with a slightly higher diameter ( from 70 to 75 ) does it throw the speedo out and lose some power. Or am I competely confused?

The 75 is the height of the sidewall expressed as a pecentage of the tread width.

Thanks for the replies all.

Originally Posted by Redback

No not confused, yes it does, throws the speedo out by 4% and yes sucks some power from the car, to bring mine back to standard power so to speak i had it chipped/ECU remapped.

If you don't tow it's not a big issue but we tow a heavy camper so the chip was a necessity.

Baz.

I don't know whether it was just a placebo effect but my car actually felt quicker with the big treads on and slugglish with the normal road treads. Yes I know it defies reason.
It definately uses more fuel with them on though.

http://www.aulro.com/app/data/616/PHTO00101.JPG

I might have come across 4 near new 245/75s BFG ATs for about 250 bucks, it they are still available I`ll bang em on, for the price I can`t go wrong.

Hi,

I'm currently running 265/70/16 Cooper St. They don't rub but look very big in the guards and you feel a tiny bit of the loss of power and the speedo is 7% wrong.

I put a 2" OME lift on and now they look too small!!!

I'm going to 265/75/16 MTRs next just for the heck of it.

Apparently it's the beginning of lower diff ratios and stronger axles...