235/40/18 on 18x8 ET34 - will it rub?

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DaveD
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235/40/18 on 18x8 ET34 - will it rub?

Post by DaveD » Thu Mar 14, 2019 4:22 pm

Hi

Looking at taking the winter wheels of my forged 18x8 405m wheels of my f30 330d and trying a square set up on my coupe. Looking to go MPSS.

Offset is ET34, so 13mm more poke than standard wheels at the front/16mm at back. M sport suspension so not low. Know they’ll be fine with 225/40/18 at the front but will 235/40/18 rub? Not a huge difference but don’t want to chance it. Know tears will be fine

Cheers

D
Z4 Coupe 3.0si SE - Stratus Grey - M sport seats, wheel, headlining, star spokes, New England, DSP, Cruise, Xenons
F30 330d M Sport - mineral grey - pro nav, HK, Visibility pack, adaptive dampers, M Sport brakes

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mr wilks
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235/40/18 on 18x8 ET34 - will it rub?

Post by mr wilks » Thu Mar 14, 2019 4:27 pm

If i was a betting man id say yes it will rub slightly but only on full compression or full lock :( it will be down to just a few mm & even the difference between brand new rubber (8mm) & part worns (4mm) can sometimes make the difference especially with et34 .
That said there are a few members running 8j et 34 fronts ( MV3s) so worth hearing their thoughts on tyre sizes to confirm :thumbsup:
E86
E85
Grey///MR
Si E85
E89 23i
Si E85
E86
3.0Si E85
Imola///MR
35i Msport 6spd
E86
Ti ///MR
E86

35is :driving:


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DaveD
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235/40/18 on 18x8 ET34 - will it rub?

Post by DaveD » Thu Mar 14, 2019 4:54 pm

Thanks Mr Wilks. I’ve got a 15mm spacers on at the moment and no rubbing with 225/40/18 but it’s getting pretty close.....
Z4 Coupe 3.0si SE - Stratus Grey - M sport seats, wheel, headlining, star spokes, New England, DSP, Cruise, Xenons
F30 330d M Sport - mineral grey - pro nav, HK, Visibility pack, adaptive dampers, M Sport brakes

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mr wilks
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235/40/18 on 18x8 ET34 - will it rub?

Post by mr wilks » Thu Mar 14, 2019 4:59 pm

DaveD wrote:
Thu Mar 14, 2019 4:54 pm
Thanks Mr Wilks. I’ve got a 15mm spacers on at the moment and no rubbing with 225/40/18 but it’s getting pretty close.....
Switching up to 235 40 18 on the 8j effectively reduces arch gap by 4mm then consider a full tread Michelin which are a wide fitting tyre (Falken / Hankook narrower ) & it will be borderline .
E86
E85
Grey///MR
Si E85
E89 23i
Si E85
E86
3.0Si E85
Imola///MR
35i Msport 6spd
E86
Ti ///MR
E86

35is :driving:


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235/40/18 on 18x8 ET34 - will it rub?

Post by Mr Tidy » Thu Mar 14, 2019 9:26 pm

Not exactly the same, but I'm running style 295s off an E89 on my Coupe with standard Sport suspension.

Fronts are 8Jx18 with ET29, but I've got 225/40 Bridgestone Potenza's on them. But with ET29 that's 5mm further out than an ET34, and a 235/40 is only going to sit 2.5mm further out than a 225 would. While a 234/40 will have a bit more sidewall. it'll only be 40% of 10mm more, so I would have thought it might be OK.

I've had them on the car 6 months now, and no rubbing at all. :D

Good luck anyway. :thumbsup:
Z4 3.0Si Sport - Coupe for added stiffness!
Current - Montego Blue, Pearl Grey, Cirrus trim & 295s. Cruise, Storage and pdc. E90 330i as a DD.
Gone - Ruby Black, Pearl Grey & 135Ms. Xenons, heated seats and Professional speakers.

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235/40/18 on 18x8 ET34 - will it rub?

Post by mr wilks » Thu Mar 14, 2019 9:50 pm

Mr Tidy wrote:
Thu Mar 14, 2019 9:26 pm
Not exactly the same, but I'm running style 295s off an E89 on my Coupe with standard Sport suspension.

Fronts are 8Jx18 with ET29, but I've got 225/40 Bridgestone Potenza's on them. But with ET29 that's 5mm further out than an ET34, and a 235/40 is only going to sit 2.5mm further out than a 225 would. While a 234/40 will have a bit more sidewall. it'll only be 40% of 10mm more, so I would have thought it might be OK.

I've had them on the car 6 months now, and no rubbing at all. :D

Good luck anyway. :thumbsup:
Either your tyres are on the wearbars or you must never drive with any spirit :P ive had the very same set up re width / offset & rolling radius on 2 different E86 Si , one lowered , one stock & both had a chaffing ( strangely only ever on drivers side :? ) when hitting twists / dips / bends at speed . Not enough to wear the liner away but noticeable to hear it
E86
E85
Grey///MR
Si E85
E89 23i
Si E85
E86
3.0Si E85
Imola///MR
35i Msport 6spd
E86
Ti ///MR
E86

35is :driving:


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235/40/18 on 18x8 ET34 - will it rub?

Post by Mr Tidy » Thu Mar 14, 2019 10:02 pm

My tyres are probably less than half worn, but I definitely do drive it with spirit - that's why I've got it! :P

Maybe I've just been lucky not to hit the right sort of dip with the driver's side wheel! :lol:

I certainly don't get any rubbing on lock.
Z4 3.0Si Sport - Coupe for added stiffness!
Current - Montego Blue, Pearl Grey, Cirrus trim & 295s. Cruise, Storage and pdc. E90 330i as a DD.
Gone - Ruby Black, Pearl Grey & 135Ms. Xenons, heated seats and Professional speakers.

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mr wilks
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235/40/18 on 18x8 ET34 - will it rub?

Post by mr wilks » Thu Mar 14, 2019 10:12 pm

Mr Tidy wrote:
Thu Mar 14, 2019 10:02 pm
My tyres are probably less than half worn, but I definitely do drive it with spirit - that's why I've got it! :P

Maybe I've just been lucky not to hit the right sort of dip with the driver's side wheel! :lol:

I certainly don't get any rubbing on lock.
Bridgestone runflats have sloped shoulders , its part of the runflat design so that will aid you & not heard Berkshire being known for its great driving roads so that too :oops: my drive is on a slope , if i reverse on full lock with car angled then i can get rub , driving off no rub , its very marginal & what can be got away with on one car may not on another even though same model . spec .
E86
E85
Grey///MR
Si E85
E89 23i
Si E85
E86
3.0Si E85
Imola///MR
35i Msport 6spd
E86
Ti ///MR
E86

35is :driving:


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235/40/18 on 18x8 ET34 - will it rub?

Post by brillomaster » Thu Mar 14, 2019 10:13 pm

hmmm slightly worried now... i was going to fit some MV3s to my e85, but my track tyres are a 245/35/18 on the front... work fine with MV1s, but will MV3s get some rubbing? :?

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235/40/18 on 18x8 ET34 - will it rub?

Post by Mr Tidy » Thu Mar 14, 2019 10:34 pm

mr wilks wrote:
Thu Mar 14, 2019 10:12 pm
Bridgestone runflats have sloped shoulders , its part of the runflat design so that will aid you & not heard Berkshire being known for its great driving roads so that too :oops: my drive is on a slope , if i reverse on full lock with car angled then i can get rub , driving off no rub , its very marginal & what can be got away with on one car may not on another even though same model . spec .
That's the problem - it seems to vary from car to car and each brand of tyres adds another variable!

We do have some good driving roads in Berkshire (admittedly not loads) but you just need to know where they are. :)
Z4 3.0Si Sport - Coupe for added stiffness!
Current - Montego Blue, Pearl Grey, Cirrus trim & 295s. Cruise, Storage and pdc. E90 330i as a DD.
Gone - Ruby Black, Pearl Grey & 135Ms. Xenons, heated seats and Professional speakers.

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235/40/18 on 18x8 ET34 - will it rub?

Post by patriot66 » Thu Mar 14, 2019 11:47 pm

I run a staggered set of MV3s on my Zed, 225/40R18 et34 8J on fronts and 255/35R18 et37 8.5J on rears. I had quite bad rubbing on the front top outside wheelarch liners on high speed compression bumps...it wore through the plastic :o I changed my Sport springs back to SE and fitted new Bilstein B4s and it has never rubbed since. Also the front Avon ZZ5s have quite a narrow and square shoulder which probably helps too. This is how the car sits now :thumbsup:
20190314_224228.png
20190314_224228.png (1.18 MiB) Viewed 167 times
'03 Sterling Grey 2.5i SE / SMG / Matching Hardtop / Gloss Black MV3s / Bilstein B4s / DLV Backbox / Carbon-wrapped Interior Trim / Re-Covered Steering Wheel / De-tango'd !

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235/40/18 on 18x8 ET34 - will it rub?

Post by DaveD » Fri Mar 15, 2019 7:21 am

patriot66 wrote:
Thu Mar 14, 2019 11:47 pm
I run a staggered set of MV3s on my Zed, 225/40R18 et34 8J on fronts and 255/35R18 et37 8.5J on rears. I had quite bad rubbing on the front top outside wheelarch liners on high speed compression bumps...it wore through the plastic :o I changed my Sport springs back to SE and fitted new Bilstein B4s and it has never rubbed since. Also the front Avon ZZ5s have quite a narrow and square shoulder which probably helps too. This is how the car sits now :thumbsup: 20190314_224228.png
Interesting. When I was running 20mm spacers up front on my OE wheels I did get rubbing (went slightly through the drivers front arch liner too) on sport springs. Back to 15mm spacers now so pretty close to ET34 now and no rubbing. That’s with 225/40/18 Michelin PS4 rubber. MPSS is a slightly squarer profile than the MPS4 from memory (had them before) so I guess even at 225/40/18 there is a risk of rubbing. I’ve got just under 2 degrees of camber up front with pins pulled. Guess I’ve always got the option of camber plates to give a bit more.

As an aside, is a hole in the wheel arch liner going to cause an issue at MOT? I’m looking for a spare on eBay but just interested.
Z4 Coupe 3.0si SE - Stratus Grey - M sport seats, wheel, headlining, star spokes, New England, DSP, Cruise, Xenons
F30 330d M Sport - mineral grey - pro nav, HK, Visibility pack, adaptive dampers, M Sport brakes

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235/40/18 on 18x8 ET34 - will it rub?

Post by philbo909 » Fri Mar 15, 2019 8:45 am

brillomaster wrote:
Thu Mar 14, 2019 10:13 pm
hmmm slightly worried now... i was going to fit some MV3s to my e85, but my track tyres are a 245/35/18 on the front... work fine with MV1s, but will MV3s get some rubbing? :?
You'll get a lot of rubbing
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235/40/18 on 18x8 ET34 - will it rub?

Post by ErrErrminator » Fri Mar 15, 2019 9:27 am

patriot66 wrote:
Thu Mar 14, 2019 11:47 pm
I run a staggered set of MV3s on my Zed, 225/40R18 et34 8J on fronts and 255/35R18 et37 8.5J on rears. I had quite bad rubbing on the front top outside wheelarch liners on high speed compression bumps...it wore through the plastic :o I changed my Sport springs back to SE and fitted new Bilstein B4s and it has never rubbed since. Also the front Avon ZZ5s have quite a narrow and square shoulder which probably helps too.
Whereas my car, on sport springs and standard shocks (I think), is running exactly the same wheel size/tyre size/offset combo and I have not had any issues with rubbing at all. Not sure I'd get away with 235 tyres up front though.

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235/40/18 on 18x8 ET34 - will it rub?

Post by brillomaster » Fri Mar 15, 2019 1:59 pm

philbo909 wrote:
Fri Mar 15, 2019 8:45 am
brillomaster wrote:
Thu Mar 14, 2019 10:13 pm
hmmm slightly worried now... i was going to fit some MV3s to my e85, but my track tyres are a 245/35/18 on the front... work fine with MV1s, but will MV3s get some rubbing? :?
You'll get a lot of rubbing
hmmm might give it a go and see... I'm not lowered, just standard SE springs I believe. patriot66's car looks great!

I could always revert to a 225/40/18 when I next need new tyres - the fronts probably have 3 trackdays left in them.

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