Another winter tire question . . .

This may be somewhat of an elementary question for some but after reading pages and pages on this topic I am still confused.

I have a 2013 50i with M Sport/M Performance with a staggered 19" set-up --

255/50 19 (front)
285/45 19 (rear)

I am looking to do the switch from summer to winter tires but have discovered that the rear tire size essentially does not exist in winter tires. On tirerack it directs me to get all four the size of the current front tires.

Here in lies the question -- by changing the size of my rear tires do I have to get new wheels?

Looking for an unbiased answer from someone that is not interesting in selling me four new wheels to go along with my winter tires.

A suggestion to you (and others with tire questions), why not post your question also on the tire specific sub-forum http://www.bimmerfest.com/forums/forumdisplay.php?f=49

Gary from TireRack moderates this forum and is very knowledgeable.

Originally Posted by vatausae

This may be somewhat of an elementary question for some but after reading pages and pages on this topic I am still confused.

I have a 2013 50i with M Sport/M Performance with a staggered 19" set-up --

255/50 19 (front)
285/45 19 (rear)

I am looking to do the switch from summer to winter tires but have discovered that the rear tire size essentially does not exist in winter tires. On tirerack it directs me to get all four the size of the current front tires.

Here in lies the question -- by changing the size of my rear tires do I have to get new wheels?

Looking for an unbiased answer from someone that is not interesting in selling me four new wheels to go along with my winter tires.

1. The front and rear tires are the same DIAMETER. (as measured in inches)

2. Going to all 4 the same size will likewise result in the same diameter (obviously)

3. The SOLE question is 'does the tire manufacturer recommend size ABC for both my X inch wide front rim and my Y inch rear rim?"

Offhand I do not know the RIM WIDTH for those wheels. (You should post them...) You need to look up the "specs" for the specific tire size/brand, and make sure the 'rim width range' covers your front and rear rims.

Sure, you can CALL and TALK to people, but if YOU want to be certain, you check it yourself based on published specs.

A

Reconsider using 19" or 20" M wheels for winter driving. Try and find some basic 18" 'take-off' wheels for your winter tires from a wrecking yard or other source. There are many more options for good 18" winter tires and it will save you a lot of up-front tire costs plus remounting wear and tear on the tires/wheels. Remounting tires 2X/year can get expensive with balancing and so forth.

The best reason to get right-sized snow tires is performance. X5 owners who do a lot of winter driving usually recommend 18's. The larger 19"+, low-profile tires have a bigger contact patch but this doesn't mean better traction when the tread isn't reaching asphalt. That's why you see a lot of pickups with monster-sized tires in the ditch. (Of course, there are other reasons…)

One last comment: Consider buying tires from a shop that will swap your tire/wheels for you each season for free.

Rich H.

FYI BMW x5 oem 18" and 19" tires are both 255 cross section. The decision you have to make is if you feel the added side wall benefits your situation. In chicago, pot hole central, the 19's have never been an issue. Since 2007, my x5 has not suffered tire/rim damage. On my old e53, I went from a 20" to 18" winters and sold them rather quickly and bought 19's because I felt they were way too soft moving from a 20 to 18. My current X5 I have 20's for summer and 19's for winter and they are a bit softer but after a day or two I really could not tell. There is no shortage of 18/19 e70 rims out there. Good news is any OEM from 2007+ will be a direct fit and you will have to decide if TPMS error EVERY TIME YOU GET IN THE CAR is worth not purchasing a set of TPMS for your winter set. P.S. just buy sensors

Originally Posted by Rich_H

Reconsider using 19" or 20" M wheels for winter driving. Try and find some basic 18" 'take-off' wheels for your winter tires from a wrecking yard or other source. There are many more options for good 18" winter tires and it will save you a lot of up-front tire costs plus remounting wear and tear on the tires/wheels. Remounting tires 2X/year can get expensive with balancing and so forth.

The best reason to get right-sized snow tires is performance. X5 owners who do a lot of winter driving usually recommend 18's. The larger 19"+, low-profile tires have a bigger contact patch but this doesn't mean better traction when the tread isn't reaching asphalt. That's why you see a lot of pickups with monster-sized tires in the ditch. (Of course, there are other reasons…)

One last comment: Consider buying tires from a shop that will swap your tire/wheels for you each season for free.

Rich H.

+1 Excellent Points