so after signing all the paperwork and bringing the car home, i realized that the car had a staggered set up, 275 in the back, 245 in the front. I thought for AWD it was a strict square set up.

These are the rims that came with the car, not sure what style number they are. Does anyone have any thoughts and perspective on the rim itself? I know the XFR Nevis rims were made of clay and bent easy. were these any different?

 

Hard to say but are they the stock sizes?
I have a 2014 XJR and those come with forged 20" staggered rims. I have hit potholes at surprising speeds and no damage yet. I currently have about 42K miles on the car.
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Those are the correct tire widths for the AWD XJ. With 19" wheels, the tires should be 245/45 19 and 275/40 19. In 20" wheels, 245/40 20 and 275/35 20.

The 20" rims have the reputation for being quite easy to bend. However, I've hit potholes without damaging them.

 

Thanks for confirming @Mark SF they are 245/40, 275/35....im just really shocked that they came staggered. All over the BMW forums, all they talk about is how the setup must be square for AWD and how staggered is bad for the system

at the moment the car shakes at around 50-70 mph, not so much the steering wheel (it does a bit), but the car overall....as if the rear rims could be bent. Also, i found an old service record from the previous owner, and it says "customer states car is shaking, all 4 rims bent"....this was back in 2015.......i guess the issue is back

also, what is the appropriate tire pressure for the 20"? 19's say 32psi

 

20s are 32 PSI also. Vibration is not necessarily the wheels... could be the tires. I've had lots of problems with Pirelli P Zero all seasons. My last X308 XJR had chronic vibration problems with those tires. I recently had the wheels Road Force balanced on my X351, and they told me one of the rear Pirellis is out of round, and it isn't the wheel.

If any wheels are bent, it should be visible at the rim. Don't forget to check the inside as well as the out.

Suggest finding a good shop with a Hunter Road Force balancer, make sure you explain the problem, and that you want to be informed if any wheels are out of spec.

I had one wheel that was out of round, got it totally refurbished for $175. They strip off the powder coat, repair any bends etc, then re-power coat. Looks like new. I imagine it might be cheaper where you are than in California.

Finally, these high performance tires tend to take a bit of a set when parked, and will then vibrate for a few miles at 50-70. It should then work its way out as they warm up.

 

i may have found the potential cause to my bumpy shaky ride situation: the tires were GROSSLY over-inflated. the 2 fronts were at 38psi.....one rear at 42, the other 32.

something makes me think that they did that on purpose to to keep them from flat spotting....and then i believe they recently refinished the tire thats currently at 32, hence why its at 32.

will go on a drive later to validate...stay tuned

 

If you look at the specs for the tires, while the rim diameter is different, the tire overall diameter is the same, and THAT is the important factor in the equation, for an AWD car.