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.

[Exonian]

I ran a set of CM Reifnitz for three years including some tough winter use.
Check with CM as mine came in ET45 not the advertised 42mm so were a more friendly offset.
ET42 is pretty tight at the front for clearance on strong compression bumps. I’ve run ET41 as well and my front arches survived so it’s not a big worry.

Going to a 40 profile on a 19” wheel is not a good idea in my opinion. As above, the Speedo will be out, your insurance will need notification and the tyre will be even closer to the arch on compression (bearing in mind the lower offset)

If they’re mostly intended as winter wheels then some Michelin cross climates might be a wiser tyre choice(?)  their sidewalls will probably be slightly more pliant than summer UHP tyres.

For reference I ran various factory 18” Bridgestone tyres on several mk7’s and had factory Pirellis on my TCR.
The Pirellis were pretty nasty and the Bridgestones not my favourite tyres.

[pixelcellar]

I ran a set of CM Reifnitz for three years including some tough winter use.
Check with CM as mine came in ET45 not the advertised 42mm so were a more friendly offset.
ET42 is pretty tight at the front for clearance on strong compression bumps. I’ve run ET41 as well and my front arches survived so it’s not a big worry.

Going to a 40 profile on a 19” wheel is not a good idea in my opinion. As above, the Speedo will be out, your insurance will need notification and the tyre will be even closer to the arch on compression (bearing in mind the lower offset)

If they’re mostly intended as winter wheels then some Michelin cross climates might be a wiser tyre choice(?)  their sidewalls will probably be slightly more pliant than summer UHP tyres.

For reference I ran various factory 18” Bridgestone tyres on several mk7’s and had factory Pirellis on my TCR.
The Pirellis were pretty nasty and the Bridgestones not my favourite tyres.

Think i'm at the point of ditching the 235/40 idea, too much hassle with potential fit and insurance, may go down to 18's which may well help a bit at some point but means buying another set of wheels!!! So for now just new tyres i think, have had PS4's on all my Golfs, agree re the Bridgestone's, they weren't great on my Polo and only drove briefly on my GTI PP(18" Austin's) before getting a set of Brescia's with PS4's.

Seems there are potentially quieter tyres now though wondering a couple of DB difference helps with noise, would it mean a more pliable tyre too and potentially help with ride over crap surfaces do you think?

[MinchCS]

I went to 18s with 235/40 SC7s on my Clubsport S. HLT Leggera ET49 (you can get them in ET 45 too if you want more poke).
Much better ride and set up is just under 12kg lighter than 19 Prets - and stronger
£2000 for whole package - wheels and tyres - delivered from Wheelbase Alloys. And perfectly balanced too.

[MinchCS]

Oops! Double post.