Octavia VRS MKIII - Tyre Size 225 or 235?

[Jimski]

Evening all, 

 

Picked up my 2014 Octavia VRS last week and its running 235/40/R18's all round on the Gemini wheels. Not sure at what point or why the change was made. 

 

Having done some Googling and researching on here, it should be running 225/40/R18's? Is this going to cause me any untoward issues? Do I need to revert back? 

 

I need to replace two due to them having cracks, so obviously the garage has priced up 235's. 

 

Mind.......blown haha!

 

Jimski

[Carlston]

2 hours ago, Jimski said:

Evening all, 

 

Picked up my 2014 Octavia VRS last week and its running 235/40/R18's all round on the Gemini wheels. Not sure at what point or why the change was made. 

 

Having done some Googling and researching on here, it should be running 225/40/R18's? Is this going to cause me any untoward issues? Do I need to revert back? 

 

I need to replace two due to them having cracks, so obviously the garage has priced up 235's. 

 

Mind.......blown haha!

 

Jimski

 

Gemini alloy rims have a specification of 7.5Jx18.

 

As you can see from the below chart, 235/40R18 has an ETRTO approved minimum rim width of 8J. So officially 7.5J is too narrow.

 

However, I doubt you will have any problems running 235/40R18 on a 7.5J rim apart from the questionable legality, as the wider but higher aspect ratio 245/45R18 can be fitted to a 7.5J rim.

 

The 235/40R18 may have been fitted for cosmetic reasons. Many VRS owners simply like the look of wider tyres. It could have been fitted to help improve ride comfort and improve resistance to pothole damage and improved resistance to kerbing damage.

 

The 235/40R18 tends to be a more expensive tyre size than 225/40R18, so cost considerations are not in favour of the wider tyre.

 

ETRTO approved rim widths

225/45R18 7.0-7.5-8.5
235/45R18 7.5-8.0-9.0
245/45R18 7.5-8.0-9.0

225/40R18 7.5-8.0-9.0
235/40R18 8.0-8.5-9.5

245/40R18 8.0-8.5-9.5

 

Edited 21 March, 2023 by Carlston

[SurreyJohn]

The correct tyres for Gemini rims should be 225/40 R18

 

Obviously if you were only planning on changing 2 of 4 tyres, then can't really run with mixed sizes.

 

I am guessing it is an everyday use car, rather than something for exciting drives on warm sunny days.   If so seriously consider changing all 4 tyres and putting all season tyres on.