OK, so I am going with some custom made forged wheels for my x5m. I get to specify offsets and widths. My goal is to get a 20x11/20x12 wheel that will not be overly aggressive and still clear the brakes and suspension.
The car is stock, and will remain that way, so no lowering. Its a street car only, I have another car for track driving.
OEM is 20x10 ET40 and 20x11 ET35 as far as I know.
I am going with 20s also due to better tire selection and preferring the look and performance of a little more tire on the wheel.
I would ideally like to run NON RFT tires, and my theory is that RFT has a distinct advantage especially on heavy cars, that the sidewall is very stiff resulting in excellent steering feel and lack of body roll.
This is a problem when going to a tire like a conti DW or a Michelin PSS. One way to get around this, is to run a wide wheel which in effect provides extra sidewall support to a NON RFT tire. So I want to run 1 inch wider wheels on stock tire sizes to alleviate the negative cornering and steering effects of a soft tire. Ive been doing this for years on other cars.
So, I want to run 20x11 and 20x12 if I can. I also want no more than 10-15mm more aggressive than stock up front and 15-20mm in the rear based on what wont look silly on the car (any pics or other ideas welcome).
Using this quick calculator, its easy to get a feel for how the chosen wheel width will compare to stock in poke (how much more it protrudes out) and more complicated, inner suspension and effectively brake caliper clearance. Wider wheels, when not offset by a lower offset, will eat up interior clearance space.
http://www.1010tires.com/Tools/Wheel-Offset-Calculator
SO, does ANYONE KNOW how much extra clearance we have, and how much space I can use up and still clear the suspension and brakes?
The below widths and offsets have the following results...
20x10 ET40 to 20x11 ET40 (fronts)
+13MM poke, -13MM interior clearance
If you go with an ET35, you can get to 18mm poke with 8mm interior clearance.
Clearly, my preference for the look I want is the 13MM poke, but giving up 13mm of interior clearance may not work.
Can anyone help? Its easy to get them to fit using 10.5 front wheel, but I don't want to do that unless I must.
Thanks guys, really need some experienced guys to help here! Trying to up the x5m wheel game! I think yall will like what I have in store