Has anyone gone 235/40/18 on the front?

[Lewy]

Hi all, as the title does anyone on here have any experience fitting these size tyres successfully on a Z with 8.5j wheels on the front?

The reason I ask, I've picked up a set of wheels (18" 8.5j) which are now in refurb and will soon be ready for some rubber (and of course some piccies!). I want to go as wide as possible to improve the stability and I know 255/35/18 is achievable on the rear although I've not seen 235s too much.

Any help will be much appreciated. Thanks in advance

[Captain]

I have 235/35/19 on 8.5" rims, on the front of mine.

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[TitanTim]

When I had the AC Schnitzers Type 3s I pondered on fitted 235s on the front but when I spoke to Rossiters when ordering the wheels they recommended 225s for the fronts as standard fitment, they are stretched slightly though on an 8.5 rim. What I found was the Zed definitely tramlined alot more than the standard 7.5 rim I had on the front which I reckon may have been down to the tyre being stretched. The Zed definitely didn't feel at its happiest. I've now got 8s on the front with 225 and its transformed and no tramlining. I don't know if going wider may exacerbate tramlining which isn't pleasant.

Tim.

[G2JRP]

On my 2.8 I fitted 18" 8.5 with an et of 35 they had 235/40 if think and they were ok but did hit the wheel each protector,

I would stick with 225's and go as big as possible on the back

[Lewy]

Thanks for the feedback fellas. Makes me a little more comfortable about trying it.

What I didn't mention is that I already have 2 x 235/40/18s with plenty of life so it's a free trial so to speak, just wanted to make sure it wasn't going to be a total misfit

[freck99]

Just seen this thread
I've got 235/40/18's on the front of mine after I bought some cheapish wheels and tyres while I have my original Type 78's refurbed.
Unfortunately they do rub slightly on full lock but it's not too bad, and they passed the MOT fine despite this.

Steve

[Lewy]

Thanks Steve, I'm hoping I'll get a bit luck with the offset but will keep an ear out for a bit of rubbing - cheers for the heads up!

[Woody1000]

I've just bought a set of 235/35/19's with an ET of 45 and fitted them last week with no problems at all ! They are tight with only around 7mm clearance to the front struts but they do fit and without spacers ! I think it's the ET offset that counts.

[Captain]

I think 235/40/18 will be to big

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[freck99]

Just a quick update, my wheels are ET 43 all round (off a 3series)
The fronts are only just within the arches, just about legal, however the rears could do with spacing out about 10-15mm.

I was contemplating spacing out the fronts slightly to avoid the rubbing but they'd be too far out.
Thankfully they're only for winter or until I've got the offset Type 78's refurbed so will do for now.

Steve

[Lewy]

Woody, those wheels look great mate

Steve cheers for that, agreed it's all in the offset - the daft thing is, I don't know the offset!

Proof of the pudding 'n all that - pick them up tomorrow!

[Woody1000]

Thanks Lewy, I picked mine up on fleebay and didn't a clue if they would fit as the guy didn't know the ET off set ! Also when I checked on line at a couple of alloy wheel fitment sites they all advised going from a 7.5 J to 8.5 J I would need spacers!

So when I finally put them on I was completely surprised that they went straight on, as I guess I took a huge gamble so I'm very lucky

You won't know until you try !!

[Lewy]

All good! No rubbing yet although eibachs arrive next week...

[ZedAintDead]

Wow, those darker alloys and gills have transformed the look, nice job!

[Captain]

Looking good

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[Lewy]

Thanks for the comments! The colour is Ferric Grey which is a BMW colour, going to find a rattle can of the same colour and redo the side gills and maybe kidney grilles too

[Del]

The wheels look good but I can’t sleep until you restore those side gills.

[Lewy]

The wheels look good but I can’t sleep until you restore those side gills.

Haha! They will be changing although maybe not quite being restored!

[Bi11]

Love the wheels. Am considering something similar staggered for the z3m

[John1950]

I have 225/40/18s on the front and 255/35/18 the rears.
These were chosen to ensure the outer wheel diameters remained essentially the same as the originals and thus keep the speedo accurate.
I would have thought if you're aiming for 235/40/18 then the fronts will be a greater diameter and may well rub against the arches. I know mine just (only just) touch when on full lock. This is accentuated if you have the car loaded and take a left or right hand rising bend as the suspension dips at the same time as the wheels are on more or less lock - the outer rim of the tyres rubs the rear of the wheel arch and can be heard.

[Lewy]

The rolling diameter is fine in regards to the guideline 2.5% either way -

235/40/18 front (+2.22% or +14mm) - (these tyres came with the wheels)
255/35/18 rear (+0.79% or 5mm)

BUT!

At higher motorway speeds the traction control is cutting in meaning that it doesn't like the difference in rolling diameter from the fronts to the rear. If the fronts are making less revolutions than the rear then the TCS thinks the rears are losing traction, so I think I do need to go for a different front.

235/35/18 would be a closer rolling diameter at a difference of +9mm from standard however 225/40/18 would be +6mm difference from standard and therefore as close as I'll get to the rear rolling diameter and maybe that'll sort the TCS problem.

Having said all this, I'm also not a fan of the handling with the extra unsprung weight of these wheels as they're only replicas and so I'll be looking out for a set of staggered CSLs and moving these on.

Enough moaning! I really do like the look though