Hi all,

New to forum so I hope this finds you all well.

Currently I have 235/35 R19' on standard xtreme alloys which I think suit the wheel size better. They certainly give a better feel/confidence on braking and spirited driving from my perspective. I have had a good search on previous posts but can't find much on going wider on the tyre profile. A fair few going smaller from 19's to 18's due to our lovely roads and potholes in the uk but little on wider tyres for 19's.

What I would ultimately like rightly or wrongly hence my question is 245/35 R19 on 8.5J up front with E45 offset (I can live with a few -% which would correct my current speedo to GPS speed). On the rear 255/30-35 R19 on 9J with E50 offset. This would give me approx 20mm positive spoke side 7mm front / 20mm rear suspension side.

I was just wondering if anyone knew or had any experience with wheel/tyre of this size? Many thanks in advance for any thoughts or knowledge.

Kind Regards

PZ

Ignoring the clearances, dropping to a 30 profile on the front is closer than a 35 is (1.7% vs 2.1%).

Going from 225 to 235 is fine, realistically. Insurance and others might have issues with you going to a 245 or 255.

That aside, I can understand increasing the size on the front tyres to increase traction, but why the rear?

Personally, if you're willing to compromise that much on fitment, etc, I'd go ahead and stick some PS4S on there.

Looking at some other places, unless you're running some platform mods, you might have issues.

This is of course not to mention that an RS3 comes with 265 on the front and 245 on the rear - wider tyres on the back really aren't going to do anything IMO, especially with the hardly complex rear suspension on MQB cars.

I have A&R 40mm lowered springs on 19 Xtremes with 20mm spacers 235 Pilot Sports, zero rub even fully loaded, you definitely could not go any bigger with out pulling an arch off

Thanks for the replies guys much appreciated.

The 255 rear was only for visual appearance as they look a little skinny imo. I didn't consider insurance if going to 245 so great point made. Will check that out.

Not planning to do this until later in the year so plenty of time to do some measuring and checking. From what you guys have mentioned max 245 all round sounds the most viable.

Many thanks

Regards

PZ

16 hours ago, Professor_Zoot said:

What I would ultimately like rightly or wrongly hence my question is 245/35 R19 on 8.5J up front with E45 offset (I can live with a few -% which would correct my current speedo to GPS speed). On the rear 255/30-35 R19 on 9J with E50 offset. This would give me approx 20mm positive spoke side 7mm front / 20mm rear suspension side.

Not sure how the ABS and TPMS firmware would react to different size front and rear tyres on the O3, it's been designed to have identical size front and rear tyres so you could end up with ABS & TPMS faults.

Yes the RS3 has different sizes but it also has different ABS firmware.

I dont believe abs and tpms firmware to be problem because I have driven with one different size wheel-tyre combo (smaller spare tire). First the TPMS though it had lost pressure but after resetting the tyre pressure thing on media player screen it was ok until I got new tire.

19" Xtremes with 235 tyres, 20mm spacers and a 40 mm drop no rubbing fully loaded as explained, clearance and stance is perfect

In theory the ABS/TPMS systems would be fine, but you might have some issues with TC and wheel speed sensors.

I'm not sure exactly, but 245 you might be into arch-rub territory. Similarly, 245 all round might be okay, but unless you can be sure of telling the car about it, I'd be wary of introducing a staggered setup - especially one that's larger on the rear. The largest tyres you can really do are 255/265, and these are on MQB track cars with modified suspension.

I mentioned this recently on another post. Skoda will have done type ratings on the Octavia with tyres from 185/60R15 (or whatever the smallest size is) right up to 225/35R19. You will probably have no issues going to 235 (lot's of people do it), but you would still need to inform insurance. Going up to 245 and above is a different story.

Hi and welcome.

If you have any issues with insurance at all for a change of wheels / tyres then please feel free to drop me a line.

Regards,

Dan.

On 01/04/2025 at 15:13, OccyVRS said:

In theory the ABS/TPMS systems would be fine, but you might have some issues with TC and wheel speed sensors.

I'm not sure exactly, but 245 you might be into arch-rub territory. Similarly, 245 all round might be okay, but unless you can be sure of telling the car about it, I'd be wary of introducing a staggered setup - especially one that's larger on the rear. The largest tyres you can really do are 255/265, and these are on MQB track cars with modified suspension.

I mentioned this recently on another post. Skoda will have done type ratings on the Octavia with tyres from 185/60R15 (or whatever the smallest size is) right up to 225/35R19. You will probably have no issues going to 235 (lot's of people do it), but you would still need to inform insurance. Going up to 245 and above is a different story.

I don’t think pursuing the staggered route is a viable option based on the feedback so far, and to be honest, I’m fine with that—it was just an idea. However, I’d like to explore the 245 options further. Looking at JonnyType2’s setup (that is seriously slammed—fair play!), along with his comment about using a 20mm spacer on top, it seems promising. Given that I’m not planning to lower mine any time soon, I don’t see why, with the increased track and correct offset, this wouldn’t be feasible.

I will do some actual measurements and CAD it up to be sure of course.

Currently run 235/35 R19's for the last few years and completely fine. A better choice imo.

Many thanks to all who have commented, by the way, it is very much appreciated and informative.

Regards

PZ

The standard 18/19" wheels are only 7.5J aren't they? Almost ET50 or something too IIRC.

You could likely stick on some 8.5J 19s, with a 245/35, go ET40 or something and be no nearer to the strut than you are now.

You could even do 9J with 255 and drop down to ET35.

1 hour ago, OccyVRS said:

The standard 18/19" wheels are only 7.5J aren't they? Almost ET50 or something too IIRC.

You could likely stick on some 8.5J 19s, with a 245/35, go ET40 or something and be no nearer to the strut than you are now.

You could even do 9J with 255 and drop down to ET35.

Yes, I believe they are (7.5J ET51) for the Xtreme 19". For 245/35, I would need 8.5J ET45, according to the web app, which makes the spoke side protrude approximately 17mm further out and the strut side move about 7mm further in (which is certainly feasible—though I'm unsure about full compression). Based on JT2's experience, this setup fits well within his geometry. With the added height and a few millimetres of spoke-side protrusion, it seems manageable.

Regards

PZ

Edited 4 April, 20251 yr by Professor_Zoot

2 hours ago, Professor_Zoot said:

For 245/35, I would need 8.5J ET45, according to the web app, which makes the spoke side protrude approximately 17mm further out and the strut side move about 7mm further in (which is certainly feasible—though I'm unsure about full compression).

ETRTO approved rim widths for passenger car tyres

225/35 7.5-8.0-9.0

235/35 8.0-8.5-9.5

235/40 8.0-8.5-9.5

245/35 8.0-8.5-9.5

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

225/35 fitted to 7.5" rim 224mm

235/35 fitted to 7.5" rim 229mm (not an ETRTO approved rim width for this tyre size)

235/40 fitted to 7.5" rim 229mm (not an ETRTO approved rim width for this tyre size)

245/35 fitted to 8" rim 242mm

245/35 fitted to 8.5" rim 248mm

Edited 4 April, 20251 yr by Carlston

You can do a 235 on a 7.5J but I'm not sure I'd do it - ideal is 215 or 225.

235 on 7.5 is not that bad. Standard set on scout is 225 on 7.0, so even less ideal but is OK. Such tire-wheel combos where the tire is noticeable wider that the wheel, give better protection for the wheel but might look and even feel less sporty. Perhaps not ideal for a RS.

Yeah, at that point you're relying on the carcass of the tyre to give much of the rigidity - alright if you've got PS4S on there, but even then, it's still not going to be the best handling setup.

If I was looking to run a 245, I'd probably be looking at a 9" wheel - nice and fat with plenty of support from the rim.

On 04/04/2025 at 19:16, Carlston said:

ETRTO approved rim widths for passenger car tyres

225/35 7.5-8.0-9.0

235/35 8.0-8.5-9.5

235/40 8.0-8.5-9.5

245/35 8.0-8.5-9.5

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

225/35 fitted to 7.5" rim 224mm

235/35 fitted to 7.5" rim 229mm (not an ETRTO approved rim width for this tyre size)

235/40 fitted to 7.5" rim 229mm (not an ETRTO approved rim width for this tyre size)

245/35 fitted to 8" rim 242mm

245/35 fitted to 8.5" rim 248mm

Thank you kindly for the helpful information.

Regards

PZ

Thank you for your insightful comments.

I have been using 235/35 tires on 7.5J rims for the past four years, despite their deviation from ETRTO (European Tyre and Rim Technical Organisation) specifications. Over this period, I have not observed any detrimental effects on performance, wear, or longevity. It is worth noting, however, that my driving habits tend to be more restrained these days - I do not engage in track sessions or aggressive driving scenarios that might expose potential limitations of this setup.

Looking ahead, I plan to upgrade to 8.5J rims later this year or early next, allowing ample time to conduct further research.

Regards

PZ