different tyre sizes

[nutrok]

sup all
on my car the front tyres are 205/55/r16's and the rears are 215/55/r16. is this abd for the car? like will it cause damage? ive just heard that on awd cars if the tryes are different sizes it roots them.
cheers

[BraindG]

hmm, i don't think its the best of ideas. i was told once upon a time, that you shouldn't even put new tyres on back compared to the front (or visa versa) cos the difference in tread will affect the differential over time.

[Nick Mann]

The wheels will be spinning at different speeds because the tyres are a different size. Therefore you put the diff under constant pressure. The more closely matched your tyres the less work your diffs will be doing.

It makes sense to assume that matched tyres will mean your diffs last longer. How much you will reduce the life of your diff by running mis-matched tyres is impossible to say.

[strapping young lad]

if the landrover diff is anything to go by the difference in tread wear is ok but different tyre sizes is a big NO NO..

i would imagine the tolerances on a 'bishi is miles better than solihull's finest so i would defo rule out tyre size differences.

[Nick VR4]

Wheel diameter (in) Tyre Width (mm) Profile (%) Tyre wall height (in) Rolling diameter (in)

16 205 55 4.44 24.88
16 215 55 4.66 25.31

= 0.43 of a inch differernce

[nutrok]

0.43"thats like 10 mm. f***k that thats how much. and thats how i bawt the car from the dealer. beta do sumthing bowt that then.
chhers

[bradc]

I was quite keen to have 225/45/18 on the front and 255/40/18 on the rear, to give the car more grip at the back, but everyone here said that even that (a .22% difference, or .75mm difference) was too much. I'd hate to think what 10mm would be like.

I'd suggest you take your car back to the dealers and say that you beleive your tyre difference will cause the diff to blow up and that they must change the tyres for you.

[nutrok]

sounds like a good idea. i realy could use a trip back to auks

[bradc]

come next saturday to the dyno day. Have a look at http://www.clubvr4.com/forum/showthread.php?p=86895

[Grinder]

Is the cost of 2 new tyres more than your round trip back to the dealer? Just a suggestion. No idea how far you have to travel dude.

[nutrok]

i duno 16"tyres are pretty expensive. in some cases more than 17"tyres but yea i duno. a trip to the dealer would be more fun. is the dyno day on the 6th bradc?

[bradc]

yeah it is. As I said, it starts at 9am, I intend to be there a little early though.