Few 18" questions

[scarlet-jester]

Hi all.

I am looking at increasing my rim size to 18”. I have had a read of several threads in here but was looking for a little clarity. I have seen that both of these configurations are possible on an 18” rim for my 06 3.0Si;
225/40/18
255/35/18

225/45/18
255/40/18

I also assume that for an unmodified car, these setups will both fit i.e. not cause any rubbing? Is the only or main factor of difference between these two setups ride quality or are the others? And now for the noob question, why do you run higher profile tires at the front than at the back?

Thanks

[mr wilks]

Hi all.

I am looking at increasing my rim size to 18”. I have had a read of several threads in here but was looking for a little clarity. I have seen that both of these configurations are possible on an 18” rim for my 06 3.0Si;
225/40/18
255/35/18

225/45/18
255/40/18

I also assume that for an unmodified car, these setups will both fit i.e. not cause any rubbing? Is the only or main factor of difference between these two setups ride quality or are the others? And now for the noob question, why do you run higher profile tires at the front than at the back?

Thanks

245 40 18 better for the stock 8.5j rears on Si , the 255 40 on the M wheels has a 9j width
Worth a read through here viewtopic.php?f=49&t=107556

[scarlet-jester]

Thanks Mr wilks. I found that article and have a read of it - very useful.

I currently have 17" but am unsure what style they are - not listed in the referenced thread. Running 225/45/17 front and back.

[kis]

Quick photo will sort out your 17” wheel mystery

What 18” wheels are you planning to run?

The profile difference? That’s the way BMW designed it. They’re stock sizes... so that’s good enough reason for me

[scarlet-jester]

I was thinking of getting 224s, main problem being where to get hold of some in NZ. I think it may be quite an expensive undertaking. There are a few similar types available on trademe in NZ such as these https://www.trademe.co.nz/motors/car-pa ... c2edfbdd45

They are similar in appearance, but ideally I would like to keep it in the correct period if that make sense. Perhaps get a affordable set and get hem re-furb'd. Keen on a 5-spoke design

[scarlet-jester]

These are my current 17" wheels

BMW alloy.jpg (107.39 KiB) Viewed 2416 times

[kis]

BMW Style 200 - 17x8J square set up. Not too sure on offset!

[Mr Tidy]

BMW Style 200 - 17x8J square set up. Not too sure on offset!

According to these guys they are a square set-up (8J x 17 all round) with an offset of 46. http://www.alloywheelsdirect.net/bmw_al ... wheel_1428

[scarlet-jester]

Sweet - thanks guys