Thanks I saw that. However, when I put in BMW X5 I don't get any hits for wheels that fit. I will give them a call.

You may not have to adjust the front. You will have to adjust the profile of the tire. by looking at the std tire equation, the profile number is a percentage of the width. If the tire width gets smaller, you i will need a larger profile to make up the difference. Example. On my 545 I have 245/35/19 on the front and 275/30/19 on the front. different widths, different profiles, same size.

That is the same setup I ran on the M3. Not sure about the 545, but going with a 285/30/19 in the rear was actually closer to the original ratios for the OEM M3 tires. Maintaining that ratio helps with the traction control system and not throwing off your speedometer.

I'm not saying I'll go with a 295 rear. I'm just trying to see what tire sizes people that run 20''s in the winter are utilizing. Basically a simple : I run 20''s in xxx/xx/20 in the front and xxx/xx/20 in the rear would suffice. Thanks.

Tirerack sells a Pirelli snow & Ice setup 315 rear and 275 front. Don't think you will notice any difference if you go from 315 to 295. Might as well stick with the original sizes if you stay on the 20"

I would agree the economics make sense. I am likely going a route very close to that, just with the factory 18" rims and a new set of 20" wheels in the spring.

My question is whether run flats or standard tires have much of an impact in winter conditions. I know the firmer sidewall impacts ride harshness; but I am curious about your experience with them in winter conditions. Any discernible pro or con with a RFT in winter.

I had RFT in winter time and I would not say the ride changed compared to other RFT in summer since the tire is designed for cold weather. I am getting the RFT's because i really don't want to be getting out of the car to change the tire in the cold if I do get a flat.

I had the Pirelli's Scorpion Snow and Ice on my E53 and those things were awesome and i drove them for 3 winters using only about 50% of the tread life on them.

I bought a set of the 20" #214 (off a X6) for my X5M for winter. Tirerack recommends 275/40/20 all around (even on the 11" rear rim). Either Blizzak or Alpines. Both options are about $210/tire.

Thanks for this information.:thumbup:

We have run NON-RFT's on both our 2007 and 2008 X5's with no problems at all. We use the factory TPMS (which need a gasket kit each time we change tires on the standard Style 210's). Both X5's have a spare, so no worries there. (Came standard on the 2007, was a $150 option on the 2008)/

We have NEVER had a flat on a snow tire, on 11 cars (and counting). Nails, yes, flats, no. Summer performance tires are another story, but never on a snow. (Prolly just jinxed myself!)

So based on my experience, I can't think of any good reason to mount RFT winter tires on an X5 (provided you have a spare). And with BMW Assist, you don't even need to get yourself dirty changing the tire.

So I contacted the dealership about winter tire recommendations today. They got back to me with the same summer size of 275f/315r. They didn't say what tire they were offering, but the quote was 3,680 swiss francs. I'm not lying, and this is just for some tires. I've done some independent searches and that quote is about 2000 more expensive than the Pirelli Ice and Snow RFTs. The dealership is having a laugh.

Anyhow, regarding the 275s on all corners, I saw that the maximum recommended width for a 275 is 10''. The rear wheel is 11''. Anyone have a comment on this?