Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: jayten1020 on 13 November 2016, 11:46:24

Title: 17" tyre size
Post by: jayten1020 on 13 November 2016, 11:46:24

My 2.6  estate has on the rears 255/45/17 are these standard stock size or not?
Cheers

Joel

Title: Re: 17" tyre size
Post by: Nick W on 13 November 2016, 11:54:50

No.
235/45 17 is the stock size. It's also used on Mondeo and Passats so  isn't hard to find

Title: Re: 17" tyre size
Post by: jayten1020 on 13 November 2016, 12:06:46

So should I take them off and refit 235/45/17?

Title: Re: 17" tyre size
Post by: Nick W on 13 November 2016, 12:22:43

If they're not rubbing anywhere, then I would just use them up.
In theory your speedo won't read correctly, but the difference is small and probably doesn't matter.

Title: Re: 17" tyre size
Post by: zirk on 13 November 2016, 12:37:24

Tyre width wont effect Speedo.

Speedo comes from the Front anyway.

As Nick say if there not rubbing and work, replace both when needed.

Title: Re: 17" tyre size
Post by: Nick W on 13 November 2016, 13:29:06

A 255/45 tyre will have a larger fitted diameter than a 235/45. This must affect the gearing, and consequently the speedo. But it's a small difference, and probably doesn't matter.

I thought the speedo was driven off the rear wheel sensors?

Title: Re: 17" tyre size
Post by: powerslinky on 13 November 2016, 14:06:19

Quote from: Nick W on 13 November 2016, 13:29:06

A 255/45 tyre will have a larger fitted diameter than a 235/45. This must affect the gearing, and consequently the speedo. But it's a small difference, and probably doesn't matter.

I thought the speedo was driven off the rear wheel sensors?

 would agree with Nick on this  . . . tyre wall height is 45% of the width  . .

So 45% of 255  is greater than 45% of 235   which would make the the O/A diameter of the wheel with a 255-45 tyre fitted slightly bigger than if a 235 - 45 was fitted .

Not sure how much of a difference it will actually make to speedo reading though :-\

Title: Re: 17" tyre size
Post by: Lazydocker on 13 November 2016, 23:29:40

Quote from: Nick W on 13 November 2016, 13:29:06

A 255/45 tyre will have a larger fitted diameter than a 235/45. This must affect the gearing, and consequently the speedo. But it's a small difference, and probably doesn't matter.

I thought the speedo was driven off the rear wheel sensors?

This ;) :y