I currently own 03' 4.4i X5.
Right now, I'm running 255 all around set up.
As of late, I have seen few X5's w/ staggered set up wheels on them.
Last night, I have seen a 4.6is with 255 front, 275 rear.

So my question is, is it safe to run a staggered set up on X5..
Because in my understanding of AWD, they're 50/50 balance in power,
and by having wider rear, the power ratio might not be safe to handle it..

I believe in 3 series and 5 series, the x-driving systems are not 50/50 balance,
rather they're 30/70 or 40/60 in my understanding, if so, does that apply to
X5 as well? and therefore, the staggering may be possible?

Look at the optional sport suspension wheel package and you will find your answer.

so yes

it still doesn't answer all my questions, though.

The answer you're looking for is that the width of the tire is irrelevant to the operation of the all-wheel drive on an X5. What's important is the overall diameter of the tire/wheel combo. So your 255/55-18's up front (29.04-inch diameter) have to be matched with some 285/50-18's (29.2-inch diameter) in the back. See? You widen the tire, so you have to lower the aspect ratio. Aspect ratio is the height of the sidewall expressed as a percentage of the width. So for the fronts, 55% of the width of 255mm is the height of the sidewall (140mm or 5.52 inches). So 18 (rim diameter) plus 11.04 (5.52 inches x 2 sidewalls) equals your overall diameter.

Enough answers? Or more questions? :D

it still doesn't answer all my questions, though.

You really had only one question. You just asked it two different ways. BMW has been and is selling X5 with staggered wheels. Therefore, you can use staggered wheels on your X5. Looks cool, rides rougher, handles better, useless in snow.

I currently own 03' 4.4i X5.
Right now, I'm running 255 all around set up.
As of late, I have seen few X5's w/ staggered set up wheels on them.
Last night, I have seen a 4.6is with 255 front, 275 rear.


I don't know what you saw, but the 4.4i with the optional sport wheels/tires runs 255/50R19front and 285/45R19rear. The 4.6iS and 4.8iS run 275/40R20front and 315/35R20rear. I've been running the 255/285 setup and it sticks like glue on tarmac. Why would you think the staggered setup is unsafe?

For the record, pre-'04 X5 (non-xDrives) have fixed 38/62 power distribution, front/rear respectively...NOT 50/50 as you've indicated. Post-'04 (xDrives) can vary power distribution from 0 to 100% to the fronts or rears on demand.

Maybe this is the question and we have been missing it. On the early X5 with fixed power distribution, can staggered wheels be used? It might upset BMW's factory suspension balance, but probably not in a very negative way. On a non AWD car, I would not worry at all, but maybe with fixed AWD, I would do further research and I have to admit that I cannot help after all. Try X5World, a website specializing in the X5.

Staggered wheels/tires have been used since the introduction of the X5 back in 1999. Staggered setup will NOT affect the powertrain if the overall rolling diameters of all wheels are kept the same as Critter7r had pointed out. The only thing that the staggered setup will affect is on the handling side, which will make the X5 understeer more (make it less tail happy) as will on any other cars, AWD or RWD. Whether understeer is a good thing depends on your driving skills. In general, it is much safer to make a car understeer than oversteer for an unskilled driver. With more meat on the road, the staggered setup also benefit from being less "tippy"...an added safety factor for a high center of gravity vehicle. With that said, it's a personal opinion that you have to judge for yourself whether you will like the staggered setup. A general statement cannot be made on it, be it positively or negatively.