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scottyv · 11-27-2009, 10:05 AM

Ok guy's here is the real deal on the X6 and aftermarket wheels.

You have two major issues to deal with

1. The hub sizes front to rear are different ever so slightly

The fronts are 74mm and the rears are 72mm (72.56 to be exact)

So if you go aftermarket you will most likely get 74mm wheels and you need centering rings for the rear.

2. There is a large offset difference front to rear on the X6.

This means if you go with the same wheels (width, no staggered) all the way around, your rear wheels will be pulled in (away from your fender edge) about 25-30mm.

If you look at the factory specs for BMW's $4,000 winter tire package for the X6, you will see they use the following

wheels (Style 232, 19")

Front 19 x 9" offset 48mm

Rear 19 x 9" offset 18mm

I went so far as to see this Style 232 setup and measure with a level to check fender to tire gaps (how far the tire is inward from the fender/wheel well edge) on this setup in person what I measured was a front tire to fender difference of 3/4" and the same for the rear (3/4"). So, to keep this the same you need a front to rear offset differential of -30mm in the rears, if you use the same width wheel front to rear.

Now when you order winter tires with narrow rubber and non staggered (all four wheels the same width) like me you will see the rear wheels pulled inward due to the offset differential (more than just the tire width would be).

here is a very helpful tool I used for some of my calculations

http://www.1010tires.com/WheelOffsetCalculator.asp

So if you plug in the sport package rear wheel numbers 315/35/20 tire with 11" x 20" offset +37mm

and compare it to the aftermarket 9.5" x 20" offset +40mm which I used for rears

you will see a outer position retraction of 22mm, in my measurements (on my own vehicle aftermarket snows vs sport rear pkg) I saw a little more (25 -28mm) as this can be because of tire manufacturers section widths do not always correspond exactly to their nominal section widths.

I don't mind this look for my winter wheels (the retraction of basically an inch), but I do notice it.

11-27-2009, 10:05 AM	#22
scottyv Modding Master 16 Rep 80 Posts Drives: 2010 X6 5.0 Join Date: Oct 2009 Location: Michigan iTrader: (0)	Ok guy's here is the real deal on the X6 and aftermarket wheels. You have two major issues to deal with 1. The hub sizes front to rear are different ever so slightly The fronts are 74mm and the rears are 72mm (72.56 to be exact) So if you go aftermarket you will most likely get 74mm wheels and you need centering rings for the rear. 2. There is a large offset difference front to rear on the X6. This means if you go with the same wheels (width, no staggered) all the way around, your rear wheels will be pulled in (away from your fender edge) about 25-30mm. If you look at the factory specs for BMW's $4,000 winter tire package for the X6, you will see they use the following wheels (Style 232, 19") Front 19 x 9" offset 48mm Rear 19 x 9" offset 18mm I went so far as to see this Style 232 setup and measure with a level to check fender to tire gaps (how far the tire is inward from the fender/wheel well edge) on this setup in person what I measured was a front tire to fender difference of 3/4" and the same for the rear (3/4"). So, to keep this the same you need a front to rear offset differential of -30mm in the rears, if you use the same width wheel front to rear. Now when you order winter tires with narrow rubber and non staggered (all four wheels the same width) like me you will see the rear wheels pulled inward due to the offset differential (more than just the tire width would be). here is a very helpful tool I used for some of my calculations http://www.1010tires.com/WheelOffsetCalculator.asp So if you plug in the sport package rear wheel numbers 315/35/20 tire with 11" x 20" offset +37mm and compare it to the aftermarket 9.5" x 20" offset +40mm which I used for rears you will see a outer position retraction of 22mm, in my measurements (on my own vehicle aftermarket snows vs sport rear pkg) I saw a little more (25 -28mm) as this can be because of tire manufacturers section widths do not always correspond exactly to their nominal section widths. I don't mind this look for my winter wheels (the retraction of basically an inch), but I do notice it. __________________ 2010 Alpine White X6 5.0 with Oyster Leather / Dark Wood Trim -- Sport Package with 20" Style 259 Wheels, Premium Pkg, Premium Sound, 7RR Performance Pkg, Active Steering, Running Boards, Rear View Cam & Top view, Cold Weather Pkg, Rear Climate Pkg, Comfort Access, Space Saver Spare, Sat Radio, Smartphone Integration Last edited by scottyv; 11-28-2009 at 05:32 AM..
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