Tyres

[silverfox8]

I have a 2010 2.3i auto and the tyres are all Potenza 225/45 R17 rf.
Is this normal and should I still go by the tyre pressures on the door pillar.
I am thinking of changing to normal tyres of the same size or should I put larger tyres on the rear.
Can any one recommend tyre pressures for non rf
Thanks
Mike

 

[Mr Tidy]

As far as I know all Z4s were fitted with Bridgestone Potenza run-flats, so the pressures on the door pillar will be correct for what you've got at present.

Sorry I can't help with your questions regarding swapping to non-RFTs - I haven't done it yet!

But I'm sure someone will be able to help.

 

[Busterboo]

Mr Tidy's dealt with your pressure question.

As for non-rfts, the consensus is that they're much better than rfts. It's certainly my experience.

Now, you need someone to answer your rear size question ...

 

[Nictrix]

As you are thinking of changing the tyres why not try to find a set of wheels with tyres in 18" or 19" sizes as they do make the car look better.

 

[Anonymous]

I have a 2010 2.3i auto and the tyres are all Potenza 225/45 R17 rf.
Is this normal and should I still go by the tyre pressures on the door pillar.
I am thinking of changing to normal tyres of the same size or should I put larger tyres on the rear.
Can any one recommend tyre pressures for non rf
Thanks
Mike

I too had a 2010 23i auto on 18” rims and the rear tyres were wider than the fronts. In fact I think this is true for all E89’s (and all Zeds) I would guess the rear tyres on yours would originally have been 255/40.

 

[Tbone]

I just got a quote for mine and the guy recommended going for 255/40's for the rear, reason he gave me for the smaller profile is that it allows the car to run level on all 4 wheels as the back wheels are bigger.

as for pressures, I dont know because I havent fitted them yet. I have a cracked M326 that needs replacing so Im going for an after market set of wheels and a full set of new rubbers (non-runflat)

Tyres Im looking at either Michelin MPS4's or Goodyear Assymetric 3's

 

[silverfox8]

Thanks all for your help.
Mr Tidy, I wasn't sure that the pressures on the rear might have come down as there is less rubber on the road.
Busterboo, I have been running snow tyres on another set of wheels and they were far more comfortable that is why I thought of going for normal tyres.
Essex Zed, I bought my car from a BMW dealer so thought the tyre sizes were ok, its just that all other Zeds I have seen have had wider tyres on the rear.
Tbone, Thanks for info on the tyres you are thinking of.

 

[Nictrix]

Essex Zed, I bought my car from a BMW dealer so thought the tyre sizes were ok, its just that all other Zeds I have seen have had wider tyres on the rear.

With it being 17" wheels you have you may not have a staggered fitment and that will be why all your tyres are the same size.

 

[Anonymous]

I looked at a 2010 Z4 brochure online and it seems the standard wheels offered on the 23i at that time were 17” Star Spoke style 290 and were 8J front and rear with 225/45 RF tyres all round, so if you have these wheels that would account for why you have the same size tyres front and rear.

The only other 17’s available then were the Turbine style 292 and these were 8.5J on the rear with 255/40 tyres.

 

[Busterboo]

18s with Michelins won't be a compromise and will cost a good bit less than 19s.

 

[silverfox8]

Thanks Nictrix, Busterboo and EssexZed
That has helped a lot, I will stick with the 17's all round and move to non rf's next month.
Thank you all for your help.

 

[Arcade.Eyes]

Any know if : 255/35R19 will fit on the rear without rubbing? All tyre purchase companies suggest 255/ 30 r 19 but if I can get some extra side wall I would for comfort.

 

[mr wilks]

Any know if : 255/35R19 will fit on the rear without rubbing? All tyre purchase companies suggest 255/ 30 r 19 but if I can get some extra side wall I would for comfort.

Assuming 9.5j & not a ridiculous offset then no problem at all , lots of clearance with increased wheel protection & ride comfort .
I always go 255 35 on 19s , no reason not to

 

[Arcade.Eyes]

Cheers , I will do too then.

 

[warmasice]

Any know if : 255/35R19 will fit on the rear without rubbing? All tyre purchase companies suggest 255/ 30 r 19 but if I can get some extra side wall I would for comfort.

Assuming 9.5j & not a ridiculous offset then no problem at all , lots of clearance with increased wheel protection & ride comfort .
I always go 255 35 on 19s , no reason not to

Mr Wilks, what size do you suggest for the fronts?

 

[mr wilks]

Any know if : 255/35R19 will fit on the rear without rubbing? All tyre purchase companies suggest 255/ 30 r 19 but if I can get some extra side wall I would for comfort.

Assuming 9.5j & not a ridiculous offset then no problem at all , lots of clearance with increased wheel protection & ride comfort .
I always go 255 35 on 19s , no reason not to

Mr Wilks, what size do you suggest for the fronts?

On style 326 ?

 

[warmasice]

Assuming 9.5j & not a ridiculous offset then no problem at all , lots of clearance with increased wheel protection & ride comfort .
I always go 255 35 on 19s , no reason not to

Mr Wilks, what size do you suggest for the fronts?

On style 326 ?

Yes. Thinking of going up on the front like the back for a more comfort and match the rolling circumference a little more. However, some have had rubbing issues at the front and so I'm confused as to what tyre size to order.

 

[mr wilks]

Mr Wilks, what size do you suggest for the fronts?

On style 326 ?

Yes. Thinking of going up on the front like the back for a more comfort and match the rolling circumference a little more. However, some have had rubbing issues at the front and so I'm confused as to what tyre size to order.

Not sure id go over 235 35 on front 8j 326

 

[warmasice]

On style 326 ?

Yes. Thinking of going up on the front like the back for a more comfort and match the rolling circumference a little more. However, some have had rubbing issues at the front and so I'm confused as to what tyre size to order.

Not sure id go over 235 35 on front 8j 326

How about 225/40? Or do you recommend keeping the front the same and just going up on the profile at the rear?

 

[mr wilks]

Yes. Thinking of going up on the front like the back for a more comfort and match the rolling circumference a little more. However, some have had rubbing issues at the front and so I'm confused as to what tyre size to order.

Not sure id go over 235 35 on front 8j 326

How about 225/40? Or do you recommend keeping the front the same and just going up on the profile at the rear?

I fitted 225 40 19 to a set of 8.5j wheels on a 23i but only to reduce arch gap without lowering springs , on Msport with 326 8j id say 235 35 was the max you would want on front without looking over tyred