Wheel Offset, 255 to 225

[Anonymous]

Hello, my first post on the forum!

I've recently bought a Z4, my first RWD, and I'm looking for winter tyres before the prices shoot up for winter...

It's the 3.0SI 2007 model, so 225/255 108 wheels. If I wanted to replace these with 225 (17" or 18") on all corners for winter, what offset would I need for the rear?

I've been researching for a while, and still none the wiser!

Would 17" be an issue over the facelift brakes? I've rear that 17s are fine but 16s won't fit.

Cheers,
Carl

 

[mr wilks]

Hello, my first post on the forum!

I've recently bought a Z4, my first RWD, and I'm looking for winter tyres before the prices shoot up for winter...

It's the 3.0SI 2007 model, so 225/255 108 wheels. If I wanted to replace these with 225 (17" or 18") on all corners for winter, what offset would I need for the rear?

I've been researching for a while, and still none the wiser!

Would 17" be an issue over the facelift brakes? I've rear that 17s are fine but 16s won't fit.

Cheers,
Carl

17s will fit Si Z4s , ideally offset I would be looking around et40/44 rears & fronts although you could go nearer etete50 with a downturn in looks or nearer et30 for a wider stanced look

 

[bmwaddict]

Hi there, welcome. As you say, 16in wheels won't fit over s.i. brakes. Wheel/tyre width is different to offset, offset is where the mounting face of the wheel is in relation to the inside/outside edge of the wheel, and therefore the depth the wheel will sit within the arch.
Hope this helps

http://www.willtheyfit.com/index.php?width=225&aspect=40&diameter=18&wheelwidth=8.0&offset=45&width2=245&aspect2=35&diameter2=18&wheelwidth2=8.5&offset2=45#isPage=1

 

[sars]

Just to clarify previous posts, your standard offset is 47 with an 17 or 18 x 8" wheel with 225/17/45 or 225/18/40 tyres

 

[dhobbs]

Hi and welcome.
I too have the si but with mv2 wheels but are the same size as 108s.
I have 17 inch 103 alloys for winter which have an offset of 47. Size are 225/45/17.
If you look at your owners manual it tells you the winter tyre and wheel size (M+S).
You can deviate from this slightly and there's good advice on the best combinations from the guys here!