E24 B7 17/8.5 wheels on E28 B7? - The Unofficial BMW M5 Messageboard (m5board.com)

sterb · 22nd October 2007, 12:46

The 17/8.5in ET11 wheels that were available as an option for the E24, do they fit the E28 B7?

I did the math and it looks OK, the ones I am looking at have 235/45/17s, just after confirmation. Difficult to say without mounting them and the wheelarches do look slightly different between the two models.
As far as I know the E28 arches are rolled at teh factory?

Thanks in advance - sterb.

jrcalvin · 23rd October 2007, 08:05

I do not think so. I had Hartge 16x8.5 et25mm with 245/45/16 tires on my e28 M5 and they were almost rubbing on the rear fender. The 17x8.5 et11mm rim will be another 14mmcloser to the fender than the Hartge rim. However, I did the run the Alpina "17" winter wheel", which is 17x8 et19mm, with 235/45/17 tires on the front and rear of my e28 M5 and they were a perfect fit. Also note that the et19mm offset is nearly the same as the BMW factory offset of 20mm for the stock e28 M5 rim (16x7.5 et20mm).

The Alpina 17x8 et19mm winter rim is then about 6mm closer to the rear fender than the stock 16x7.5 et20mm rim.

jrcalvin · 23rd October 2007, 08:17

I just read the last post by AG on "My first trip with B7 Turbo Coupe" and he had a link on his post with photos from the August OGP and the first OGP photo showed an Alpina e28 with what appeared, to me anyway, to have Alpina 17 x 8.5 rims on it. Check it out.

A.G · 23rd October 2007, 08:32

I had 8,5 x 17 with 235/45 and 9,5 x 17 with 255/40 x17 on my old B7 E28 , but then the back fenders where rolled on the inside otherwise they have been "rubbing"

sterb · 23rd October 2007, 11:10

Quote:

Originally Posted by jrcalvin

I do not think so. I had Hartge 16x8.5 et25mm with 245/45/16 tires on my e28 M5 and they were almost rubbing on the rear fender. The 17x8.5 et11mm rim will be another 14mmcloser to the fender than the Hartge rim.

Would an et11 not be 14mm further away from the arch than et25? I always thought the et is the distance the rim is pushed out from the axle, is et not measured from the middle of the rim to the end of the axle where the rim is mounted?

Quote:

Originally Posted by A.G

I had 8,5 x 17 with 235/45 and 9,5 x 17 with 255/40 x17 on my old B7 E28 , but then the back fenders where rolled on the inside otherwise they have been "rubbing"

Can you remember what et those wheels where?

Thanks in advance.

sterb · 23rd October 2007, 11:12

Found this, in german but it shows how ET is measured.

A.G · 23rd October 2007, 13:10

I Don´t remember the ET, but it was a "standard " set from a B10 E34 .

Yannick · 23rd October 2007, 14:51

Quote:

Would an et11 not be 14mm further away from the arch than et25? I always thought the et is the distance the rim is pushed out from the axle, is et not measured from the middle of the rim to the end of the axle where the rim is mounted?

Can you imagine a fictive line exactly crossing in the middle of your wheel? This is ET zero (Line 1 on the German picture attached by Sterb). ET is always measured from this fictive line which is the ET reference line.

The more ET you have, the more the inner part of the wheel will move towards the shock. For this reason and to avoid a contact between the inner wheel part and the shocks, it is sometimes necessary to install spacers that will "push" the wheel outside.

Have a look at this easy explanation and kindly move the mouse pointer on ET 00, ET 30 and ET50.. look how does the wheel move and what happens !

http://www.tuning.org/pneu_jante/et.php

sterb · 23rd October 2007, 15:25

Thanks Yannick - now I get it

bendeco · 29th October 2007, 16:03

Sterb - I use the 17x8.5 et11 wheels with 235/45/17 Michelins on my 635CSi and have no fitment problems whatsoever. They even clear the M6 front brakes I've upgraded to (16x7 et11 open lugs do not - they require a spacer to clear the calipers). Anyhow, anything that will work on an e24 should work the same on an e28...