19" tyre sizes for CSL reps

[BDswarveP]

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

 

[mr wilks]

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

 

[STUBOY2UK]

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

 

[mr wilks]

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

 

[MrPT]

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/1WWM15-_1UHg-BDaRVeIW22vwzhFEZic7hW7NXc_y5Sk/edit?pli=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!

 

[STUBOY2UK]

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.

 

[mr wilks]

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

 

[STUBOY2UK]

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

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!

 

[zedfourthreelitre]

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

 

[STUBOY2UK]

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:

 

[zedfourthreelitre]

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.

 

[MrPT]

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!

 

[STUBOY2UK]

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!

 

[Wrs]

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.

 

[zedfourthreelitre]

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.

 

[MrPT]

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.

Ah, yeah you're right, sorry. Guess that's one of the reasons why the non-M rides slightly lower as well.

On the downside as zedfourthreelitre said above, they do look slightly 'baloony' and there is very little clearance around the arches.

:worthless:

 

[stevespg]

I'm also thinking about CSL, have found the below setup which all purport to fit the z4....can anyone confirm if any of these offsets will likely work fine with tyres suggested .all suggest they fit z4 bust offsets vary so much. I've no plans to lower

from automotive wheels
19 X 8.5J 5X120 ET37 ALLOY WHEELS
19 X 9.5J 5X120 ET30 ALLOY WHEELS

also these from autoworx
19X8.5 FRONT ET35 AND
19X9.5 ET38

also these from BM autopsport
19" x 8.5" et38 front
19" x 9.5" et45

TYRES SIZE (probably but open to suggestion)
235/35/19 FRONT
265/30/19 REAR


thanks all.

 

[mr wilks]

I would go with either 2 or 3 of the above sets but not no1
Front tyres on 19s 8.5 i would go for 225 35 to avoid possible arch rub when suspension is under compression
Rears i would be going 255 35 but that's my preference for comfort , alloy protection & if not lowering it also reduces arch gap
Others may prefer less rubber :wink:

Hers my last Si roady (not lowered) on 19s although 8j & 9js with et's 38/40

 

[STUBOY2UK]

Here we go, just for reference!

Wheel is 9.5j 19"

The top picture is 265/35/19. They felt great and the ride was much more forgiving, however they looked a little 'balloony' for me and because I'm lowered on Eibach, they were too close to the arches for comfort. I'm sure they would be fine on standard springs, and possibly M springs.

The bottom pic is 265/30/19 which look great and don't rub, but the ride is pretty harsh.

 

[Z4M-2006]

Visually the bottom ones look better..

The tops ones look like the wrong tyre has been fitted...