Hey, want to upgrade my wheels, get a 235/40/19, 8.5j, 43et instead of my 205/55/17, 7j, 46et.

Anyone done this? Will they fit?

Tried an online tire calculator and it said the outside will stick out 22mm and the inner 16mm.

Thanks

As you can see in the chart below, 235/40R19 fitted to an 8.5" rim width is 17mm wider than a 225/40R19 fitted to a 7.5" rim width.

However, the ET43 reduces the offset by 5mm compared to the ET48 which means that the standard 19" wheels on the Octavia MK4 need at least 13.5mm of clearance on the outside and at least 3.5mm of clearance on the inside for no rubbing to occur with the 235/40R19 8.5Jx19 ET43 wheel.

If 15mm wheel spacers can be used with the standard 19" wheels without rubbing, I expect 235/40R19 8.5Jx19 ET43 wheels without wheel spacers can also be used without rubbing.

Fitting 235/40R19 to slightly narrower 8.0" rims would help the clearances...so perhaps first try 235/40R19 8Jx19 ET44 wheels from the Superb MK3/MK4.

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

225/40R19 fitted to 7.5" rim 224mm

235/40R19 fitted to 8.0" rim 235mm

235/40R19 fitted to 8.5" rim 241mm

245/40R19 fitted to 8.0" rim 242mm

Outside diameter of tyres

225/40R19 662.6mm

235/40R19 670.6mm (1.2% bigger outside diameter compared to 225/40R19)

245/40R19 678.6mm (2.4% bigger outside diameter compared to 225/40R19)

ETRTO approved rim widths for passenger car tyres

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

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

245/40R19 8Jx19 ET44 wheels fitted to Superb MK3 (lowered and with wheel spacers)

Edited 15 October, 202515 Oct by Carlston