I've been thinking about getting a set of aftermarket wheels that won't break the bank for a while (and avoid dealing with things like hubcentric spacers, PCD adapters, etc), and settled on some Milanni Clutch 475 rims. I'm pretty sure these will work, just wanted second thoughts on a couple aspects before spending money and having even more issues. Specifically looking at p/n 475-8812GM20

First, bore. Milanni lists bore at 74.1mm, if I remember right some sites list Jag OEM bore at 73.9... Will this work OK, without causing vibrations from being uncentered by .1-.2mm? Will I have to use some shim stock to take up that .1mm gap? I've been having nagging vibration issues for a while, so trying to dot my i's and cross my t's here.

Second, offset. There's two offsets available, +38 and +20. I believe OEM offset was +33 on an 8in wide rim. In my head +38 makes more sense to keep everything "factory spec"; the Clutch's are 8.5" wide, so offsetting the rim by an extra 0.25in ~ 6 mm, almost to that +38 spec, would keep the tire "centerline" nearly the same as factory. The rims that came on my car had some unknown crazy low offset, which negatively affected steering, especially at low speeds. However, wheel sites only list the +20mm as being compatible with the x308's. If that offset wouldn't cause issues (prefer firsthand experience on this one), I'd rather go with the +20. They seem to be easier to find, and who knows, maybe one day I'll go for the Brembo retrofit...

 

The Jag centre bore is 73.8 mm. The Jag wheels use cylindrical nuts (not tapered nuts which would centre the rim by themselves) with some clearance so the rims rely heavily on the centre bore to be kept centered. If the wheels you think of buying use tapered nuts, then the chance of vibration is rather small. As for the offset, the closer to the factory spec (33 mm) the better but deviations by ~ 5 mm will not really affect the steering

 

Sounds good. Pretty sure they are tapered on the aftermarket ones.

After staring at this a few more times, and checking some wheel sites, I realized my offset logic was backwards. +33mm on an 8" wide rim would equate to about a +28 on an 8.5" wide rim. 20mm offset option it is!

 

Bigger offset brings the wheel further in, smaller offset further out.

At 33 offset and 8" width, the wheel outer edge is at certain position in relation to the body (the wheel arch).
At 33 offset and 8.5" width, the wheel outer edge will be 0.25" (6.35 mm) further out.
At 28 offset and 8.5" width, the wheel outer edge will be 6.35 mm + 5 mm (total 11.35 mm) further out.
At 20 offset and 8.5" width, the wheel outer edge will be 6.35 mm + 13 mm (total 19.35 mm) further out.

If you want to maintain about the same position of the wheel outer edge in relation to the body (the wheel arch) with 8.5" wide wheels, you will need 38 offset (39.35 to be exact),

 

And this is why I asked for my math to be double checked thought about this a bunch before, and got it right the first time, then come home after a long day and get all my math backwards.

I'll try to get one of the +38 offset wheels and double check fitment before ordering the rest of the set. Will check back in once that happens, may be a bit though, other priorities, bills to pay etc.

 

Would the +20 offset wheels cause issues with fitment/handling? Seems like they're out of stock of the correct part with no ETA for stock, and I'm not seeing it elsewhere, but I might be able to get a set of the +20 offset wheels...