205/55/R17 @ 7J ET46. Now at 225/45/R18 @ 8J ET46.

I've just ordered some 19x8.5 ET45 alloys for mine, should have them in about a week. Then I've just got to choose between putting 225x40x19 or 225x35x19 tyres on them. I was originally thinking 245x35x19 but the alloy wheel maker doesn't have these listed in their certification. Strange, since same wheelsize from DOTZ does give that as an option in their certified tyre sizes.

I'll be able to add some pics in about a week or so, tyres I'm between choosing Toyo Proxes Sport 2 or Yokohama Advan Sport V107.

Edited 6 May, 20251 yr by scatmanwalks

12 hours ago, scatmanwalks said:

I've just ordered some 19x8.5 ET45 alloys for mine, should have them in about a week. Then I've just got to choose between putting 225x40x19 or 225x35x19 tyres on them. I was originally thinking 245x35x19 but the alloy wheel maker doesn't have these listed in their certification. Strange, since same wheelsize from DOTZ does give that as an option in their certified tyre sizes.

I'll be able to add some pics in about a week or so, tyres I'm between choosing Toyo Proxes Sport 2 or Yokohama Advan Sport V107.

225/35R19 is an Octavia MK3 tyre size, whereas 225/40R19 is an Octavia MK4 tyre size.

As you can see in the chart below, the outside diameter of 225/35R19 is too small for the Octavia MK4.

Outside diameter of tyre

225/40R19 662.6mm

225/35R19 640.1mm (3.4% smaller outside diameter compared to 225/40R19)

Edited 6 May, 20251 yr by Carlston

Yep, what I'm more worried about is the rim width. At 8.5 a 225 measured width is 8 inch, so putting a 225x40 means stretching, so you end up with the tyre wall pulling outwards towards the rim. For 8.5 rims, they suggest ideal width of being 235 or 245, with 225 being the absolute minimum. Obviously putting a 225x40 with a stretch is going to be better than attempting to stretch a 225x35 (obviously not including the fact of whether it was for the MK3 or MK4).

I'm more inclined to put the 235 after reading, and ensuring my rim safety, since stretching means with the wall stretch I have more risk of kerbing.

13 hours ago, scatmanwalks said:

Yep, what I'm more worried about is the rim width. At 8.5 a 225 measured width is 8 inch, so putting a 225x40 means stretching, so you end up with the tyre wall pulling outwards towards the rim. For 8.5 rims, they suggest ideal width of being 235 or 245, with 225 being the absolute minimum. Obviously putting a 225x40 with a stretch is going to be better than attempting to stretch a 225x35 (obviously not including the fact of whether it was for the MK3 or MK4).

I'm more inclined to put the 235 after reading, and ensuring my rim safety, since stretching means with the wall stretch I have more risk of kerbing.

The only authority on what tyre sizes can be fitted to what rim widths is ETRTO (European Tyre and Rim Technical Organisation). Even the car manufacturers including VAG aren't allowed to go outside ETRTO's recommendations.

As you can see in the chart below, 215/40 and 215/35 can both be fitted to an 8.5" rim width.

What you can fit to a particular rim width doesn't just depends on the tyre's width but also on the tyre's aspect ratio . For example, a 225/50 can't be fitted to a 8.5" rim width, but a 225/45, 225/40, and 225/35 can.

VAG will rarely fit a tyre to the maximum rim width...and for good reasons.

ETRTO approved rim widths for passenger car tyres

50 Series

215/50 6.0-7.0-7.5
225/50 6.0-7.0-8.0
235/50 6.5-7.5-8.5
245/50 7.0-7.5-8.5

45 Series

215/45 7.0-7.0-8.0
225/45 7.0-7.5-8.5
235/45 7.5-8.0-9.0
245/45 7.5-8.0-9.0

40 Series

215/40 7.0-7.5-8.5
225/40 7.5-8.0-9.0
235/40 8.0-8.5-9.5
245/40 8.0-8.5-9.5

35 Series

215/35 7.0-7.5-8.5
225/35 7.5-8.0-9.0
235/35 8.0-8.5-9.5
245/35 8.0-8.5-9.5

Edited 8 May, 20251 yr by Carlston

OK thx for the extra info. Rims arrive today, so I'll put them on the car tyreless and then see what kind of clearance I've got. I've seen on tyrestretch.com how 225x40x19 look on a 8.5 rim and the stretch can show too much of the rim edge. This is why I feel the 235 will be better since extra 1cm width than the 225, less stretch. Not as wide as the 245 which may or may not require wheelarch modification. But I'll know more when I mount the rim as to which way to go.

10 hours ago, scatmanwalks said:

OK thx for the extra info. Rims arrive today, so I'll put them on the car tyreless and then see what kind of clearance I've got. I've seen on tyrestretch.com how 225x40x19 look on a 8.5 rim and the stretch can show too much of the rim edge. This is why I feel the 235 will be better since extra 1cm width than the 225, less stretch. Not as wide as the 245 which may or may not require wheelarch modification. But I'll know more when I mount the rim as to which way to go.

Nominally, a 235 tyre is 10mm wider than a 225 tyre. However, the actual inflated width of a tyre always depends on what rim width it is fitted to.

As you can see in the chart below, a 235/40R19 fitted to an 8.5" rim width is actually only 5mm wider than a 225/40R19 fitted to an 8.5" rim width.

Notice also, that a 235/40R19 fitted to an 8.5" rim width is actually 11mm wider than a 225/40R19 fitted to an 8" rim width...and a 235/40R19 fitted to an 8.5" rim width is actually 17mm wider than a 225/40R19 fitted to a 7.5" rim width.

Actual inflated width of tyre (measured sidewall to sidewall, at the widest point)

225/40R19 fitted to 7.5" rim width 224mm

225/40R19 fitted to 8" rim width 230mm

225/40R19 fitted to 8.5" rim width 236mm

235/40R19 fitted to 8.5" rim width 241mm

Edited 8 May, 20251 yr by Carlston

Thought I'd just add my pic here to show how the wheels look. Keskin KT24 19" 8.5J ET45 with Toyo Proxes Sport 2 225x40x19 tyres.