Min & Max tyre sizes

[rickprice]

Folks,

I have a MY2000 4.5 and need to replace tyres. Currently the back has 225/50/R16 on them. It has standard R15 front and R16 rear Estorils.

A couple of questions:

Reducing the 50 to, say, 45 will just reduce a bit of ride height and compliance? No reason for concern as long as they are equal L-R?

Is 225 the only width that can go on the wheels?

Cheers and happy new year.

Richard

[bobfather]

Your speedo will read high too. Why would you want this, just for street cred? You'll bottom out easily too, there's hardly any clearance as is

[rickprice]

It’s not about street cred, it’s just that the 45’s are more readily available in a marching tyre so I don’t have to change all 4.

[bobfather]

rickprice said:

It’s not about street cred, it’s just that the 45’s are more readily available in a marching tyre so I don’t have to change all 4.

235 45 16 would give you your ride height back, they should fit the rim but may touch the wheel arch

[sixor8]

Between 2013 and 2017, I had a Chimaera with 245 / 45 x 16" on the rear. Most advice is that 245 is too wide for a 7.5" wide wheel but I never had issues, and no rubbing, although not all cars are the same! It was common to use these when the supply of 225 / 50 x 16" Z rated tyres became scarce.

The early Chimaeras had 225 / 55 x 16 on the rear so diameter is not really a major problem.

[TJC46]

bobfather said:

235 45 16 would give you your ride height back, they should fit the rim but may touch the wheel arch

Going wider on the tyre would not affect the height.

225/45/16 and 235/45/16 are both still the same height, 45 being the sidewall height of the tyre and 16 being the size of the wheel.

The 235 is the width. i.e just 10mm wider.

I think thats right.?....... anyone correct this please if not.

[Classic Chim]

TJC46 said:

Going wider on the tyre would not affect the height.

225/45/16 and 235/45/16 are both still the same height, 45 being the sidewall height of the tyre and 16 being the size of the wheel.

The 235 is the width. i.e just 10mm wider.

I think thats right.?....... anyone correct this please if not.

I seem to recall it’s an aspect ratio of the width of the tyre.
235/45/16 is about 9 mm bigger Diameter than a 225/45/16 which equates to about 4.5 mm ride height gain and the same for wheel arch loss.


Use Will it fit.com to compare sizes.

Edited by Classic Chim on Sunday 1st January 12:29

[bobfather]

TJC46 said:

bobfather said:

235 45 16 would give you your ride height back, they should fit the rim but may touch the wheel arch

Going wider on the tyre would not affect the height.

225/45/16 and 235/45/16 are both still the same height, 45 being the sidewall height of the tyre and 16 being the size of the wheel.

The 235 is the width. i.e just 10mm wider.

I think thats right.?....... anyone correct this please if not.

Yes it does, that's the point. The middle number (profile) is the percentage of wall height to tread width. If you increase the tread width you must decrease the profile to retain the same rolling diameter

Use this site to work out what profile change is needed to retain rolling diameter when changing tyre width

https://www.wheel-size.com/calc/

Edited by bobfather on Sunday 1st January 14:11

[TJC46]

bobfather said:

Yes it does, that's the point. The middle number (profile) is the percentage of wall height to tread width. If you increase the tread width you must decrease the profile to retain the same rolling diameter

Use this site to work out what profile change is needed to retain rolling diameter when changing tyre width

https://www.wheel-size.com/calc/

Edited by bobfather on Sunday 1st January 14:11

Thanks for that, you learn something new every day. I had no idea the width of the tyre had an impact on the height, but looking at your link it makes ...a bit.....more sense.