Tyre widths on same axle..

[brightspark]

do what i do change them in matched pairs and theres no question of braking in the wet and causing one to grip better than the other due to diferential wear or a diffrent tread pattern or make

 

[Wozzaaah]

Hello Wozzaaah,

"Sorry Alec but it is NOT the tread!
The rim the tyre is mounted to is irrelevant, it's the nominal section width measured from sidewall to sidewall."

The reason I mentioned the rim width is a poster mentioned that the 185 in this instance was rim width, which it cannot be. If you are correct and it is wall to wall that dimension is either for a specific rim width or unmounted?

Alec

I'm sure it's unmounted as, like you say, the wall to wall width will change when mounted on a wider or narrower rim but don't forget it also changes due to load and pressure, which is why it's a nominal figure, not a real-world one.
When I mentioned irrelevant I meant it in the sense that tyre designers can't factor in the exact rim width their product will be mounted on.

 

[Stoneward]

Yes they are the same diameter (tested side by side, upright on the floor, with a spirit level).
So are they OK or not??

 

[penfold]

Yes they are the same diameter (tested side by side, upright on the floor, with a spirit level).
So are they OK or not??

Depends what you mean by ok; having tyres of different make/tread pattern on the same axle isn't a good idea but it's not illegal. There's a risk of braking and handling problems if the tyres' grip levels differ, which is increased in the wet or at high speed.

 

[Wozzaaah]

Yes they are the same diameter (tested side by side, upright on the floor, with a spirit level).
So are they OK or not??

Just fit them, they're fine!!

 

[Shox Dr]

take a walk over to The car Bibles.com there's a few pages there, that tells you everything you would ever want to know about tyres rims etc etc.



I'll post this AGAIN, just in case no one bothered to read it


here's a link incase you can't be arsed to google it

I'll post this AGAIN, just in case no one bothered to read it


here's a link incase you can't be arsed to google it.






.

 

[dannyp]

as long as the numbers on the sidewall are the same it's legal.

i run 195/50/15's on my pet car. have 3 sets of rims with diffrent tyers on each set of rims, according to the numbers on teh sidewals they are all the same size, in reality they arn't but probaly near enough.

as for diffrent tyers of same size on same axel is legal it's not allways a good idea, if you mix " super sticky drive's like it's on rails and lifts the paint of the garage floor tyers" with bargain basement ditchfinders it's not going to end well. the better the tyers the more inportant matching them is.

on my daily hack, there is a diffrent make of boot on each corner they are all bargain basement crap and it drives remakably evenly i put this down to all the cheep tyers being equaly rubbish. the pet car behaves exactly the same on it's standing about wheels as tehy are all equaly rubbish ismatched crap. but mix and match compotion tyers or top end road tyers you really really notice it