Tyre Sizes

01-09-2008, 18:02

Apologies if this is a stupid question but can the same size tyre differ in diameter /height between different manufacturers? I read something along these lines in an article sometime ago and cant remember details - believe its something to do with where the measurements are taken from.

Having recently spent a weekend driving in deep ruts in south wales and dragging the diff . in the mud at points I'm thinking of increasing my tyres size from 265/70 x16 to 265/75 x16 which should increase the overall tyre diameter/height by 26.5mm - giving me an extra 13.25 mm in the side wall and therefore this amount of additional clearance under the diff - not much but something. Obviously if Brand A is physically bigger than Brand B it would increase this amount - I presume.

Thought about going to 285/75's but have been advised that this could cause the fronts to foul.

zippy656 · 01-09-2008, 18:25

hi, i know as they wear they get a lot smaller. so new tyres of any size are bigger than old ones of the same size.

i use 235 / 70 16s. can i change to 265 / 70 16s without fitting spacers or lifting??

Steve

Terranosaurus · 01-09-2008, 18:26

Yes different tyre manufacturers tyres can vary quite significantly, remoulds in particular can be a fair bit bigger than nominal.

Some manufacturers list actual circumferences on their websites etc so you can compare. Mr Tyre on Difflock recently listed the supposed ranges or each size, the thread should be fairly easy to find in their tyre section.

01-09-2008, 18:02	#1
Fill Guest Posts: n/a	Tyre Sizes Apologies if this is a stupid question but can the same size tyre differ in diameter /height between different manufacturers? I read something along these lines in an article sometime ago and cant remember details - believe its something to do with where the measurements are taken from. Having recently spent a weekend driving in deep ruts in south wales and dragging the diff . in the mud at points I'm thinking of increasing my tyres size from 265/70 x16 to 265/75 x16 which should increase the overall tyre diameter/height by 26.5mm - giving me an extra 13.25 mm in the side wall and therefore this amount of additional clearance under the diff - not much but something. Obviously if Brand A is physically bigger than Brand B it would increase this amount - I presume. Thought about going to 285/75's but have been advised that this could cause the fronts to foul.

01-09-2008, 18:25	#2
zippy656 Senior Member Join Date: Aug 2008 Location: Devizes Wiltshire Vehicle: Nissan Note Ntec 1.5 Posts: 14,137	tyre sizes hi, i know as they wear they get a lot smaller. so new tyres of any size are bigger than old ones of the same size. i use 235 / 70 16s. can i change to 265 / 70 16s without fitting spacers or lifting?? Steve

01-09-2008, 18:26	#3
Terranosaurus Senior Member Join Date: Aug 2006 Location: YORKSHIRE Vehicle: 2001 2.7 TDi T2 SWB Posts: 4,077	Yes different tyre manufacturers tyres can vary quite significantly, remoulds in particular can be a fair bit bigger than nominal. Some manufacturers list actual circumferences on their websites etc so you can compare. Mr Tyre on Difflock recently listed the supposed ranges or each size, the thread should be fairly easy to find in their tyre section.