[ahmedb]

Is anyone running 4x front 19" wheels such as 313's/MV4's etc? One of my family members is fed up of cracking rears and I wonder if it's possible to run 4x fronts on either a square tyre setup or 225 fronts and 235 rears?

[rasa bmw]

course it is,,ive run 225-40-18 on an e46 for a few years,,and i know some have went with a square set up on the wheels also its only half an inch

[ahmedb]

Cool thanks

[rasa bmw]

Originally Posted by ahmedb

Cool thanks

ive got mv3 on my e90 and style 189 on my 335d,,been ok for me,,seems like 19 inch are worse and even worse with runflats...ive got some japan racing JR20 arriving in the next few days,,8.5j et35 and 9.5j et35 18 inch wheels in hyper black for my e92 335d se space grey,,hope they stay crack free like my originals

[therealdb1]

Of course the 19" will be worse than 18" as there is less rubber between the road surface and the rim of the wheel.
The rolling diameter needs to be kept roughly the same so that electronics associated with wheel rotation like your ABS, traction and speed indication are not affected.
When cars had 15" rims and 85 profile tyres rims never cracked but if you fit those to your BMW you will look like a muppet!

[rasa bmw]

gonzo?

[ahmedb]

Originally Posted by therealdb1

Of course the 19" will be worse than 18" as there is less rubber between the road surface and the rim of the wheel.
The rolling diameter needs to be kept roughly the same so that electronics associated with wheel rotation like your ABS, traction and speed indication are not affected.
When cars had 15" rims and 85 profile tyres rims never cracked but if you fit those to your BMW you will look like a muppet!

If we ran 4x fronts, all on 225/35/19 tyres or maybe 235/35/19 rears, would that cause significant issues?

[therealdb1]

You don't say which car this is for.

If it is for one of the lower powered models I think I would probably stick with a square set up.

Back of an envelope calculation suggests that the rolling circumference difference between a 225/35/19 and the usual 255/30/19 rear is 14mm with the rear being the smaller of the two.

The difference between 225/35/19 and 235/35/19 is 22mm with the rears being larger.

In any case the 235 will only give you an extra 4mm of rubber between road and rim than the 225, or 6mm more than a 255/30/19.

Is that enough to prevent cracking?

I don't know the answer but for what it is worth if the driver is regularly cracking rims then perhaps the better option is to change to 18" rims.

[ahmedb]

Originally Posted by therealdb1

You don't say which car this is for.

If it is for one of the lower powered models I think I would probably stick with a square set up.

Back of an envelope calculation suggests that the rolling circumference difference between a 225/35/19 and the usual 255/30/19 rear is 14mm with the rear being the smaller of the two.

The difference between 225/35/19 and 235/35/19 is 22mm with the rears being larger.

In any case the 235 will only give you an extra 4mm of rubber between road and rim than the 225, or 6mm more than a 255/30/19.

Is that enough to prevent cracking?

I don't know the answer but for what it is worth if the driver is regularly cracking rims then perhaps the better option is to change to 18" rims.

It's for an E93 LCI 330d M Sport on M Sport suspension.