Tyre size for new trackday rims - Cupra 290

[jesusdm20]

Hi! Nice to meet you all.

This is my first post here, so i hope to do it good!

I have a 2020 290cv leon cupra, which i use as daily and sometimes i run at trackdays. Now it have 235/35 R19 8J width rims. I found the opportunity to buy a 18" 7.5J alloys from an original cupra (winter pack). I was thinking in to buy it because they re really cheap (250€).

The idea is maintain the 19 8J for daily use and put 18 7.5j for track use. My question is:

Can I fit 235/40 R18 tyres on 7.5J new rims? I know that for 7.5J the recommended rim size is 225, but, will be 225 enough for track use for stock cupra?.

Thank you. Cheers from Spain!

 

[H Rafiq]

I use VW Cadiz rims from a Golf R on my Cupra 280 daily. They’re 225/40 R18. Very comfortable as there’s much more tyre wall, and less prone to kerbing too. Also plenty of grip with them. One of the best mods I’ve done. They replaced my stock 235/35 R19 which were very harsh and prone to kerbing.

 

[jesusdm20]

I use VW Cadiz rims from a Golf R on my Cupra 280 daily. They’re 225/40 R18. Very comfortable as there’s much more tyre wall, and less prone to kerbing too. Also plenty of grip with them. One of the best mods I’ve done. They replaced my stock 235/35 R19 which were very harsh and prone to kerbing.

Thank you for your reply. Have you tested on trackdays?

You think 235 is too much to wear on 7.5j alloys?

 

[SuperV8]

Thank you for your reply. Have you tested on trackdays?

You think 235 is too much to wear on 7.5j alloys?

The tyre manufactures usually provide data for their tyres - on what they think is the acceptable rim width allowance.

Goodyear for example quote:
Approved Rim Width (in.)8.0-9.5 for their 235/40R18 Eagle F1

Nankang mirror this: with 8 - 9.5j rim for 235/40

Going with a wide tyre on a narrow wheel will reduce your steering feel and precision.
Rubber compound will have a much greater effect in traction than a 10mm reduction in width.

 

[jesusdm20]

The tyre manufactures usually provide data for their tyres - on what they think is the acceptable rim width allowance.

Goodyear for example quote:
Approved Rim Width (in.)8.0-9.5 for their 235/40R18 Eagle F1

Nankang mirror this: with 8 - 9.5j rim for 235/40
View attachment 40230

Going with a wide tyre on a narrow wheel will reduce your steering feel and precision.
Rubber compound will have a much greater effect in traction than a 10mm reduction in width.

Thank you for your reply! Yes, maybe I must use 225. You think guys if 225 is enough for my cupra and trackdays?