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19" tyre sizes for CSL reps

Alloy wheels and tyre discussion
BDswarveP
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19" tyre sizes for CSL reps

Post by BDswarveP » Fri Oct 21, 2016 7:57 pm

Alright I'm just after some advice on tyre choice for some CSL reps.

19" staggered CSL reps et40 offset rears, haven't got full details atm.

Cars currently on stock suspension, but depending on gap between tyre and arch it might end up getting lowered. Really don't want to ruin the ride quality and end up with rattly shack.

So I'm wanting to get as much rubber round the rims without any scrubbing.

Was just wondering if someone could advise as to which size tyres are best.

And also what brand? Non run flats.

I've seen some threads suggesting the following:

235 40 19 fronts & 255 35 19 rears
Or
235 35 19 fronts & 265 35 19 rears

Or any other combination?

Any help much appreciated

Cheers

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mr wilks
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19" tyre sizes for CSL reps

Post by mr wilks » Fri Oct 21, 2016 10:53 pm

Rim width plays a big part , i prefer 8j & 9j on E85 E86 but a majority of aftermarket alloys are 8.5j & 9.5j which prompts wider rubber
The rear wheels won't be a problem on et 40 whether 9 or 9.5j so go 255 35 19 or 265 35 19
Fronts you really need the offset & width to determine tyre size as they can easily rub on the light cover in arch liner if slightly oversized
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19" tyre sizes for CSL reps

Post by STUBOY2UK » Mon Oct 24, 2016 11:33 am

Mr Wilks, could you run a 275/30/19 on a 9.5j rear wheel?
Z4R 3.0si Sport auto. So far: 19" CSLs, Eibachs, MM exhaust tips, de-badged rear, stubby, black grilles, spacers, aux cable, interior LEDs, LED boot strip......

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19" tyre sizes for CSL reps

Post by mr wilks » Mon Oct 24, 2016 12:18 pm

STUBOY2UK wrote:Mr Wilks, could you run a 275/30/19 on a 9.5j rear wheel?

No reason why not , its the max recommended width for a 9.5j but the 30 profile will help . Its a very similar rolling radius to a 255 35 on 9.5j
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19" tyre sizes for CSL reps

Post by MrPT » Mon Oct 24, 2016 12:41 pm

285/30 on 9.5J has been done too, although the logical choice for the front (assuming 8.5J) would then be 245/35, which probably needs a minor arch roll. Lots of examples here: https://docs.google.com/spreadsheets/d/ ... li=1#gid=0

As MW says, it's the fronts which can be pretty tight. Even stock tyres will rub slightly on full lock if the car is lowered or has front spacers.

To go to 19s and preserve the ride quality you really want 265/35 rears, which may mean a bit of a visual mismatch between the front and rear sidewall heights. Bothers some people more than others!
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
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19" tyre sizes for CSL reps

Post by STUBOY2UK » Mon Oct 24, 2016 1:22 pm

MrPT wrote: To go to 19s and preserve the ride quality you really want 265/35 rears, which may mean a bit of a visual mismatch between the front and rear sidewall heights. Bothers some people more than others!
Tempted to do this. My rears need replacing soon and if I could make the ride even just a touch more forgiving, I think it would be worth it.
Z4R 3.0si Sport auto. So far: 19" CSLs, Eibachs, MM exhaust tips, de-badged rear, stubby, black grilles, spacers, aux cable, interior LEDs, LED boot strip......

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19" tyre sizes for CSL reps

Post by mr wilks » Mon Oct 24, 2016 2:14 pm

STUBOY2UK wrote:
MrPT wrote: To go to 19s and preserve the ride quality you really want 265/35 rears, which may mean a bit of a visual mismatch between the front and rear sidewall heights. Bothers some people more than others!
Tempted to do this. My rears need replacing soon and if I could make the ride even just a touch more forgiving, I think it would be worth it.
265 35s would be my ideal for 9.5s , i ran 255 35s on 9.5j on the M roady with no issues & both wheel + arches would have taken the extra bit of rubber no question
Currently on 255 35 19s on Si which are perfect but they're 9j :thumbsup:
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19" tyre sizes for CSL reps

Post by STUBOY2UK » Thu Dec 08, 2016 3:25 pm

mr wilks wrote:
STUBOY2UK wrote:
MrPT wrote: To go to 19s and preserve the ride quality you really want 265/35 rears, which may mean a bit of a visual mismatch between the front and rear sidewall heights. Bothers some people more than others!
Tempted to do this. My rears need replacing soon and if I could make the ride even just a touch more forgiving, I think it would be worth it.
265 35s would be my ideal for 9.5s , i ran 255 35s on 9.5j on the M roady with no issues & both wheel + arches would have taken the extra bit of rubber no question
Currently on 255 35 19s on Si which are perfect but they're 9j :thumbsup:
Just had 265 35 19s fitted, ET 40, 9.5j, lowered on Eibach and they just about fit! Going to try them out over a few uneven surfaces later to see if they rub. My initial thoughts are that 255 would have been safer!
Z4R 3.0si Sport auto. So far: 19" CSLs, Eibachs, MM exhaust tips, de-badged rear, stubby, black grilles, spacers, aux cable, interior LEDs, LED boot strip......

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19" tyre sizes for CSL reps

Post by zedfourthreelitre » Thu Dec 08, 2016 3:38 pm

265/30 is a much more sensible choice to match the rolling circumferance - a 265/35 is too baloony IMO.

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19" tyre sizes for CSL reps

Post by STUBOY2UK » Thu Dec 08, 2016 3:45 pm

I had 265 30 and the ride is just too harsh for me, hence trying to add a bit more rubber, think I may have overdone it though :? :lol:
Z4R 3.0si Sport auto. So far: 19" CSLs, Eibachs, MM exhaust tips, de-badged rear, stubby, black grilles, spacers, aux cable, interior LEDs, LED boot strip......

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19" tyre sizes for CSL reps

Post by zedfourthreelitre » Thu Dec 08, 2016 4:14 pm

STUBOY2UK wrote:I had 265 30 and the ride is just too harsh for me, hence trying to add a bit more rubber, think I may have overdone it though :? :lol:
Fair enough. Its a slim tyre but is more equivilent to the 255/35/18 which comes standard or other variants 17" etc on non-m cars.

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19" tyre sizes for CSL reps

Post by MrPT » Fri Dec 09, 2016 1:36 am

STUBOY2UK wrote:I had 265 30 and the ride is just too harsh for me, hence trying to add a bit more rubber, think I may have overdone it though :? :lol:
Interested to see how it goes. It's only a few mm over stock, whereas 265/30 is almost 2cm under!
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
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19" tyre sizes for CSL reps

Post by STUBOY2UK » Fri Dec 09, 2016 12:13 pm

Did my usual 35 mile commute this morning and it feels a lot more forgiving with 265 35 on, the ride is still very firm but they've just taken the edge off the crashiness. On the downside as zedfourthreelitre said above, they do look slightly 'baloony' and there is very little clearance around the arches. I think 255 35s would be absolutely spot on.

I should point out that mine's a daily driver so I'm reviewing these from that point of view rather than weekend hooning!
Z4R 3.0si Sport auto. So far: 19" CSLs, Eibachs, MM exhaust tips, de-badged rear, stubby, black grilles, spacers, aux cable, interior LEDs, LED boot strip......

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19" tyre sizes for CSL reps

Post by Wrs » Fri Dec 09, 2016 12:57 pm

I did have 235/35 on the front & 255/35 on the rear fitted to my 19" Atomic CSL's (as recommended by Mr Wilks). No complaints from me.
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19" tyre sizes for CSL reps

Post by zedfourthreelitre » Fri Dec 09, 2016 1:01 pm

MrPT wrote:
STUBOY2UK wrote:I had 265 30 and the ride is just too harsh for me, hence trying to add a bit more rubber, think I may have overdone it though :? :lol:
Interested to see how it goes. It's only a few mm over stock, whereas 265/30 is almost 2cm under!
For a Z4M maybe. For a Normal Z4 a 265/30 is almost perfectly comparable to a 255/35 which would have been OEM.

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