Tyre Sizes on TCR

[pixelcellar]

I'm looking to get a 'Winter' set of Reifnitz from CM Wheels or similar that are 19" X 8J 5X112 ET42 as opposed to the standard ET50 genuine wheels.

First question is, will these fit well and not stick out beyond the wheel arch's and second, is there enough clearance for 235/40/R19 tyres, i currently run 235/35/R19 on the genuine ones but loking to try and fill the arch a bit more.

Anyone with a TCR done this or know someone who did? Issues etc.

Obviously as it's lower than a standard GTI as standard i wanted to get some info before making an expensive purchasing mistake.

[Adam T7]

Have you spoken with CM wheels? I mithered them to death re. clearance / bore size / caliper clearance and bolt fit before I purchased the 19” ‘Pretorias’ a few months ago. Fit is perfect with zero issues. I know you are fitting a different wheel, but the knowledge and customer service at CM is spot on.

[SRGTD]

@pixelcellar - Below are the results from the calculator on www.willtheyfit.com of fitting the wheel/tyre combination you’re proposing to fit compared to your existing wheel / tyre setup;



You’ll see that fitting tyres with a higher sidewall height increases the radius and circumference of your car’s wheel / tyre combination which will result in a speedometer error; with your proposed setup the speedo will under-read by 3.6% so the indicated speed displayed will be less than the true speed being travelled. I’m assuming you’re in the UK - be aware that from a legal perspective in the UK, while it is permissible for a car’s speedo to over-read by up to a pre-defined margin, it must not under-read by any amount (presumably to stop drivers unknowingly exceeding the speed limit) - see article at the link below;

https://www.thecarexpert.co.uk/how-accurate-is-a-car-speedometer/

[pixelcellar]

Have you spoken with CM wheels? I mithered them to death re. clearance / bore size / caliper clearance and bolt fit before I purchased the 19” ‘Pretorias’ a few months ago. Fit is perfect with zero issues. I know you are fitting a different wheel, but the knowledge and customer service at CM is spot on.

I've not spoken to them to be fair but from SRGTD's post it looks like they'll jut out more which is annoying as that will have them jutting out i think. Will need to check.

Thought i'd ask here as more TCR owners about that may have added CM wheels or the higher profile.

[pixelcellar]

@pixelcellar - Below are the results from the calculator on www.willtheyfit.com of fitting the wheel/tyre combination you’re proposing to fit compared to your existing wheel / tyre setup;



You’ll see that fitting tyres with a higher sidewall height increases the radius and circumference of your car’s wheel / tyre combination which will result in a speedometer error; with your proposed setup the speedo will under-read by 3.6% so the indicated speed displayed will be less than the true speed being travelled. I’m assuming you’re in the UK - be aware that from a legal perspective in the UK, while it is permissible for a car’s speedo to over-read by up to a pre-defined margin, it must not under-read by any amount (presumably to stop drivers unknowingly exceeding the speed limit) - see article at the link below;

https://www.thecarexpert.co.uk/how-accurate-is-a-car-speedometer/

I did know about the speedo under/over reading, this tool is useful though for the offset workings, thanks for sharing as i'd not seen that before.

May have to scrap the 40's idea then, maybe just need a quieter tyre than a PS4 if i can't have more rubber, any ideas?

[SRGTD]

I had a set of PS4 fitted to my Polo GTI+ shortly after buying the car and never found them to be particularly noisy - certainly quieter than the Bridgestones they replaced. IMHO PS4 are a very good all round tyre when considering other important factors such as ride comfort, handling, braking performance in wet and dry conditions and wear rate. Hopefully other forum members with different brand(s) of tyres fitted to their GTi’s will contribute to this discussion topic.

Might also be worth having a look at websites such as www.tyrereviews.com for alternatives to PS4 and see how they score - not just on noise levels but on other important factors such as those listed above. There are usually some group tyre test review videos on that site too.