Cupra 300 235wheels on et40 ?

[fr.bogdan23]

Hello, i'm quite new here, and i also got the car just recently.... can someone help me please with this....i currently have 225/35/r19 et45 8.5j and i found some rims that are 8j et40 i also bought 1 week ago some new blizzak lm005 235/40/18 and i'm afraid it won't fit on the rims i wish, i'm thinking to risk and buy the rims, go to a shop and try to fit it but i would like an opinion before i do this...
Currently 225/35/r19 et45 8.5j
what i want to run: 235/40/18 et40 8j

also current shocks are Eibach pro kit 10/15mm drop

 

[rafletcher]

The ET40 rims are fine as you show, they’re narrower than your current rims and don’t poke out. And 235 on an 8” rim is perfect, I think your 225 on 8.5 is too narrow a tyre.

 

[fr.bogdan23]

The ET40 rims are fine as you show, they’re narrower than your current rims and don’t poke out. And 235 on an 8” rim is perfect, I think your 225 on 8.5 is too narrow a tyre.

Definitely, I just bought the car with this setup, I'll sell the current 19r wheels.
I was just worried because now the wheel(rubber) will poke out 10mm more because it's 235mm vs 225mm and et 40 vs 45 (currently) so it might rub on the arches? Or smth like that?

 

[fr.bogdan23]

My bad, to clarify I'm not worried if the wheel will fit on the rims, I'm afraid that now the wheel will rub on the arches( the part above wheel) because now the wheel is a little bit wider and et lower

 

[rafletcher]

You have shown on the diagram at the top they won’t. The tyre is wider, but the ET being 40 pulls it in - you’ll have zero issues. The OD of the tyre is basically unchanged.

 

[fr.bogdan23]

You have shown on the diagram at the top they won’t. The tyre is wider, but the ET being 40 pulls it in - you’ll have zero issues. The OD of the tyre is basically unchanged.

actually if i'm right lower ET pulls the rims outside of the car, not inside so being a lower ET it will push the wheel a little bit to the exterior...since my concern

 

[rafletcher]

You’re worrying over nothing. Really.

 

[BigJase88]

actually if i'm right lower ET pulls the rims outside of the car, not inside so being a lower ET it will push the wheel a little bit to the exterior...since my concern View attachment 34556

Correct lower ET = more poke.

A 235/40/19 will be too tall

A 235/35/19 is what you want. 40 profile tyres will be too big

 

[fr.bogdan23]

Correct lower ET = more poke.

A 235/40/19 will be too tall

A 235/35/19 is what you want. 40 profile tyres will be too big

My mistake again :/ .. But the picture with diagram was ok, I want to run 235/40/18 not 19)

 

[BigJase88]

My mistake again :/ .. But the picture with diagram was ok, I want to run 235/40/18 not 19)

Oh yeah 235/40/18 should be okay

 

[Damo H]

Did you mean 235/40 R19 (what you wrote in your post) or 235/40 R18 (What you put into https://www.willtheyfit.com/ )

If you meant to R19, then you need to adjust the details on https://www.willtheyfit.com/ to see that 235/40 R19 is much bigger tyre.

If you meant 235/35 R18 feel free to ignore all of the below:




I would disagree with the 235/40 R19 being a suitable tyre choice. You are not only going for a wider tyre, but a higher sidewall. As the 35 and 40 is a percentage of the tyres section width you are getting two jumps in tyre size.

Also as the ET40 8" wide rim will squash the width of the tyre more, the tyre will be much closer to the arch (rather than the stretched of the 225 over 8.5" so you are more likely to catch if you hit bug bumps and/or using lowering springs.

ET40 8" should be fine, but I would be going for the same tyre as the Cupra runs, 235/35 R19. It will actually be further away from the arch (wheel wise if not tyre).

 

[fr.bogdan23]

Did you mean 235/40 R19 (what you wrote in your post) or 235/40 R18 (What you put into https://www.willtheyfit.com/ )

If you meant to R19, then you need to adjust the details on https://www.willtheyfit.com/ to see that 235/40 R19 is much bigger tyre.

If you meant 235/35 R18 feel free to ignore all of the below:




I would disagree with the 235/40 R19 being a suitable tyre choice. You are not only going for a wider tyre, but a higher sidewall. As the 35 and 40 is a percentage of the tyres section width you are getting two jumps in tyre size.

View attachment 34567

Also as the ET40 8" wide rim will squash the width of the tyre more, the tyre will be much closer to the arch (rather than the stretched of the 225 over 8.5" so you are more likely to catch if you hit bug bumps and/or using lowering springs.

ET40 8" should be fine, but I would be going for the same tyre as the Cupra runs, 235/35 R19. It will actually be further away from the arch (wheel wise if not tyre).

definitely R18 ) i'm not going back to R19 never again because in my country is impossible to run without stress on those sizes )
I was just worried because i'll get 10mm extra of wheel and it might rub with 235/40/18 8j et40 because now i have 225/35/19 8.5j et45 and i'm quite close to the arches as you can see from the photos (or it's only in my head)

 

[Damo H]

definitely R18 ) i'm not going back to R19 never again because in my country is impossible to run without stress on those sizes )
I was just worried because i'll get 10mm extra of wheel and it might rub with 235/40/18 8j et40 because now i have 225/35/19 8.5j et45 and i'm quite close to the arches as you can see from the photos (or it's only in my head)

Ahh makes more sense. Edited the Typo for you

One thing you need to consider is that not all tyres are the same size despite the sizes lol

I ran some 215/35 R18 falkens once on a MINI, and they measured narrower than the 205/40 that I swapped them for.

The same happened on my white ST. It came with Kumhos on the front, yet the same 235/35 Michelin PSS that replaced them was a much squarer tyre so appeared a lot wider.

So to big a tyre on a rim may squash it too much, similar the 225 on the 8.5 is stretched to much.

I think 235 on 8" is completely fine (its stock measurements), but because of the tyre profile you may find you have more or less room, all depends on the tyre.

Sadly few manufacturers of tyre provide the exact measurements of their tyres online. Its been years since I've seen them (did lots of checks for my MINI 10+ years ago when they were more readily available.).

However, I would be more than optimistic that the 235/40 R18 will be fine with the ET40 based on the measurement calculations from willtheyfit.