Warning about winter tire size fitment

[Trips]

Hey Guys,

Bought some Pirelli Ice and Snows 275/40/20 x4 to place onto my stockers for the winter. I was hoping to run the same width all the way around for traction purposes.

Anyways, spent all day today trying to get the 275/40/20 put on my rears, no luck at my dealer and at two local tire shops! Although Pirelli states this size will fit onto an 11" rim, each place I brought it to could not get the tire to seat, so no luck.

I called Tire Rack and they are going to exchange these for the OEM rear size 315/35/20.

Just wanted to let people know.

_Toms

[nom3rcy]

I would be interested to hear how well that rear setup works in built up snow and slush, seems the extra width could cause flotation issues.

[RTC]

Why don't you guys stick with the OEM recommended 19'' winter tire set ?
I would also rather use H speed index winter tires than the BMW used V speed index ones.

[998M]

Here is the US the X5M comes standard with 20". I think he is not looking to buy new rims. I am running the 275/40/20 Pirelli Ice and Snows all around on the stock 20". While the tire place did complain the it was difficult, they got it on and it works great.

I didn't go with the 315 because TireRack did have them in stock when I went to buy them.

[Trips]

Yup, got some summer kicks on order and was planning on using the stockers as my winter set-up.

998M, great to hear they were able to get the 275s on the rear for you. I'm tired of going around and having these shops keep mounting and unmounting my tires only to tell me they can't do it.

Tire Rack just got some 315s in stock so I'm going to go that route. Aware of the flotation issues with the wider rears, but, hey, still better than running summer tires.

_Tom

[RTC]

In Germany, the X5 M comes on 20'' rims too. Unfortunately it is very risky to swap tires (summer to winter and vice versa) on the same rim. The reason is simple: you can damage the tire (especially low profile, high speed index tires are at risk) and this damage is usually invisible to the eye. It is recommended to keep two tire sets, one for winter and one for summer. I know this means a lot of money but if you don't want to go for the expensive BMW rims, there are alternatives out there on the market which are cheaper (rims).

[X5rolls]

Some tire shops will use an inflatable belt strapped around the middle of the tred while they are trying to inflate it on the rim. This contracts the center of the tire and pushes the lip closer to the rim where it needs to seat. Then add a blast of air to push the tire onto the rim and tire seals it enough to inflate. Did this myself before.

[DoctaM3]

Originally Posted by RTC

Why don't you guys stick with the OEM recommended 19'' winter tire set ?
I would also rather use H speed index winter tires than the BMW used V speed index ones.

I thought so too. I bought the Pirelli Scorpion Ice in the stock sports setup, i.e. 20" and they are absolutely rock solid. They work well, and no drama which you would expect from such a wide tire. Definitely would not run the performance tires in the winter, but snows, and the Pirelli's rock, are the way to go.

[RTC]

Originally Posted by X5rolls

Some tire shops will use an inflatable belt strapped around the middle of the tred while they are trying to inflate it on the rim. This contracts the center of the tire and pushes the lip closer to the rim where it needs to seat. Then add a blast of air to push the tire onto the rim and tire seals it enough to inflate. Did this myself before.

There is no safe method on the market to 100% avoid damage when swapping tires. A lot of tires shops are also using the "good old" method, removing the tire by excessive force and trust me, some of those guys who do it usually have an IQ of a Wiener Schnitzel from my experience. Don't expect them to pay attention to avoid damage.

Would be too risky for me...

[998M]

I would agree. I do not like a lot of swapping. Not to speak for Trips but I think he is doing the same thing I did. Remove the 20" summer tire that came on the OEM 20" rim and put on a winter tire. Then use this setup for winter only. I don't think Trips and I know I am not, going to be swapping back and forth. I run a 21" for the summer. I do they same for my M3. I have a 19" street summer, 18" winter and a 18" track tire/wheel combo.

The trick is what to do with the brand new 20" stock summer tires you take off. Either sell them or I would like to put them on something for a track day.

Trips, Not sure I would worry too much about the larger size rear. Unless you are driving in snow all the time. I live in WI and while it is cold I am only driving in deep slow a couple of times a winter. If you lived in the UP Michigan it could be a problem.

I did have to drive the X5M home from Chicago in the snow on the summer tires. I have driven worse.