[nidfix]

Originally Posted by ///M Houbi

Nope

go 2.5 all around if you‘re alone in the car. You will have much better traction!

I will probably down to 2.6 in the back. But I am reluctant to go 2.5 all around. In the past, with my M135i I had perfect grip at the "lowest recommended"... but I killed the sides of the tyres so quickly...

[Poochie]

Winter tires have a softer compound than MPPS summer tires..

With winter tires, I immediate lost that quick steering feedback and the DSC light flashes more often than before but I did gain a more comfortable ride and the assurance that I won't spin out in freezing temperatures..

Nothing is wrong with your vehicle, it's just the nature of the tires..

That said, I can't wait until springtime so I could get rid of them and regain that control I lost..

[dcmac]

Don't mean to hijack the thread.. but do your M2's feel 'slower' once you put on your winters? I don't mean cornering ability (which is obviously hugely affected and to be expected)... I mean just general driving the car feels slower when I step on it and I was wondering if it's the different rubber...

[bri1042]

Originally Posted by dcmac

Don't mean to hijack the thread.. but do your M2's feel 'slower' once you put on your winters? I don't mean cornering ability (which is obviously hugely affected and to be expected)... I mean just general driving the car feels slower when I step on it and I was wondering if it's the different rubber...

A little, yes, mostly when the ambient temperature is too high for these tires. I'd also put it down to the tires not being broken in yet, and the skinnier rears not being able to get the power down as well. My winters are still getting broken in but they have almost 200 miles on them now and stability is a bit improved from my initial post but depending on the temperatures outside, the car feels restrained, for lack of a better word. We had a "heat wave" yesterday (temps got above 55 degrees) and performance was impacted all around. When I got home, the treads were rather soft to the touch.

But, I could be wrong. I've been driving more cautiously since putting these.

[doug_999]

Wider tires are not better if you get ice on those rainy 30 degree days.

https://blog.tirerack.com/blog/hunte...ter-for-winter

[doughboy]

It's to be expected on winters. Softer tread blocks, less lateral grip etc.

There is always a compromise to be made in these things.

My old tuned 335i was a hoot on winters, yes a bit slidey and soft but very controllable at and beyond the limit of grip. Lots of TC light flashing. And if you did slide, the way it regained grip was tremendous even on ice and water.

On summers when you slide it just floats on the water layer and you're off into the nearest ditch..

Enjoy the winters for what they are and relish spring time when it comes...

[Transfer]

Originally Posted by doug_999

Wider tires are not better if you get ice on those rainy 30 degree days.

https://blog.tirerack.com/blog/hunte...ter-for-winter

How does less contact patch help with a solid surface? The only scenario I see where narrower tires would be better is one in which it's possible to cut through to pavement. Slush, loose or fluffy snow makes sense to be narrower. Compact snow/ice, wet roads, dry roads all are better served with more tread on the ground IMO but I'm no physics mathemagician.

[doughboy]

It's more to do with tyre ground pressure.

Narrower tyre's exert a higher pressure on the ground for a given vehicle weight, this will help expel the water layer that forms between tyre and ice and promote a more complete contact patch giving better traction in those conditions. A narrower winter tyre will also use the higher pressure to "dig in" to pack snow and ice and get better traction below the icey top layer that way. Whereas a wider tyre will spin on top of the snow.

A wider tyre is more likely to ride up on top of any water layer loosing grip.

But then a wider tyre has more grip when it has good direct contact with tarmac with a little snow / ice. So in different situations either can be better..

If you have varied snow / ice / wet tarmac / mild temp's then there will always be a compromise to make.

[doug_999]

Originally Posted by Transfer

How does less contact patch help with a solid surface? The only scenario I see where narrower tires would be better is one in which it's possible to cut through to pavement. Slush, loose or fluffy snow makes sense to be narrower. Compact snow/ice, wet roads, dry roads all are better served with more tread on the ground IMO but I'm no physics mathemagician.

The link I posted has most of what you are asking - however, to highlight
"Another way to think about this is from the perspective of the contact patch. A tire's contact patch or "footprint" greatly influences its performance. On the same vehicle, the area of the contact patch essentially remains the same with different width tires. When the footprint gets narrower as it will with a narrower width tire, it has to get longer. And the mechanics of the longer footprint help with the longitudinal traction for acceleration and braking. "

From here

https://blog.tirerack.com/blog/hunte...ter-for-winter

[chris719]

BMWs winter setup is a little stupid. Using 4 front 437 or 788M with 245 all around or 245/255 is closer to original diameter and better. The front wheels fit perfectly as rears and are only 2mm more recessed.

I question the need to go to 235s while running performance winter tires. IMO if you really need good snow performance you’re going to want a real winter tire like the Xi3. The performance winters won’t kill you, but are closer to an all season then a Blizzak WS80 or Michelin Xi3 Type tire.

[bri1042]

My drive home from work yesterday afternoon warranted an update to this thread:

The weather in Portland has been pretty weird (even for weird Portland), but the sky decided to dump the day's worth of rain on me during my 25 minute drive home yesterday, with temps between 39 and 41 degrees during the drive. My tires have about 350 miles on them now, so they're broken-in or close to it.

Short answer: These tires are fantastic in heavy rain on a cool but not frozen afternoon. I hit one really impressive puddle that caused the newer RAV-4 in front of me to skitter about and my car barely flinched. I was driving carefully, of course, but not overly slowly. I'm deeply pleased. Temps are going down this week, with a possibility of some snow next Saturday, so I should get a better idea how the car and the Alpin's handle winter-ish weather.

[mr_lab_rat]

I'm gonna hijack the thread a bit.
I put square winter setup on (18x9 with 245/40/18 Blizzak WS80).
The front felt really twitchy and light but got better as the tires were scrubbed a bit.
I don't mind the more tail happy nature of the square setup but I'm experiencing really weird problems with traction in straight line.

In lower gears I can hook up with just minimal wheel spin and TC interference. But when I'm cruising in 6th gear at 2500RPMs and floor it the car refuses to accelerate. TC kicks in and I'm not going anywhere (mostly dry road, above freezing temps).

Is anyone else experiencing the same thing? Could it be some DTC confusion from the square setup? The stock staggered setup has noticeably larger rolling diameter for the rear tires so the rear wheel actually spins a bit slower than the front. With square setup the rears rotate as fast as the fronts so the DTC could see it as wheel spin.

I didn't expect such drastic change in grip.

[///M Houbi]

Originally Posted by mr_lab_rat

I'm gonna hijack the thread a bit.
I put square winter setup on (18x9 with 245/40/18 Blizzak WS80).
The front felt really twitchy and light but got better as the tires were scrubbed a bit.
I don't mind the more tail happy nature of the square setup but I'm experiencing really weird problems with traction in straight line.

In lower gears I can hook up with just minimal wheel spin and TC interference. But when I'm cruising in 6th gear at 2500RPMs and floor it the car refuses to accelerate. TC kicks in and I'm not going anywhere (mostly dry road, above freezing temps).

Is anyone else experiencing the same thing? Could it be some DTC confusion from the square setup? The stock staggered setup has noticeably larger rolling diameter for the rear tires so the rear wheel actually spins a bit slower than the front. With square setup the rears rotate as fast as the fronts so the DTC could see it as wheel spin.

I didn't expect such drastic change in grip.

i did experience exactly the same issues. I got my car delivered with around 45psi instead of 36psi, but trusted my dealer to do it right... I couldn't accelerate on the highway no matter what. Once I set the correct pressure all traction/acceleration issues where gone.

Check your tyre pressure

[mr_lab_rat]

Thanks unfortunately that's not it. I checked my pressures when I got the wheels/tires.

[///M Houbi]

Weird. Your description matches exactly what i had as well.

[mr_lab_rat]

Originally Posted by ///M Houbi

Weird. Your description matches exactly what i had as well.

Did you make a thread about your issue? If you could point me to it I could see other responses in case someone else dealt with the same thing

[///M Houbi]

No extra thread but mentioned it here and there.

Can you manually check pressure to be 100% sure?

[doug_999]

I had something similar recently but it was while the TPMS was resetting. So maybe check
Pressures and do a TPMS reset. I also agree, the different sizes bmw allows are crazy in terms of diameter changes.

[Chasing Dreams]

Originally Posted by mr_lab_rat

I'm gonna hijack the thread a bit.
I put square winter setup on (18x9 with 245/40/18 Blizzak WS80).
The front felt really twitchy and light but got better as the tires were scrubbed a bit.
I don't mind the more tail happy nature of the square setup but I'm experiencing really weird problems with traction in straight line.

In lower gears I can hook up with just minimal wheel spin and TC interference. But when I'm cruising in 6th gear at 2500RPMs and floor it the car refuses to accelerate. TC kicks in and I'm not going anywhere (mostly dry road, above freezing temps).

Is anyone else experiencing the same thing? Could it be some DTC confusion from the square setup? The stock staggered setup has noticeably larger rolling diameter for the rear tires so the rear wheel actually spins a bit slower than the front. With square setup the rears rotate as fast as the fronts so the DTC could see it as wheel spin.

I didn't expect such drastic change in grip.

I have zero issues with my 18" square setup. Much more traction than my PSS in wet conditions.
I do need to point out that I got this wheel setup from new and the TPMS immediately threw a warning. Took it to a gas station to check tire pressure and they were on 3.2 Bar around. The pressure chart in the door says I need to be on 2.1 and 2.2 Bar.

Picture for attention:

IMG_7977 by Chasing Dreams, on Flickr

[mr_lab_rat]

Originally Posted by ///M Houbi

i did experience exactly the same issues. I got my car delivered with around 45psi instead of 36psi, but trusted my dealer to do it right... I couldn't accelerate on the highway no matter what. Once I set the correct pressure all traction/acceleration issues where gone.

Check your tyre pressure

Guess what. My tire gauge was wrong! I thought I was running 35 but the actual pressure was 40PSI.

Bringing the pressure down to what it should be solved a lot of issues I had with my winter setup (high speed stability, low speed grip, twitchy steering).
Strange thing is that I used the same faulty tire gauge on my summer tires and they handled the extra pressure without too many problems.

[stefan]

There is a reason that the official package offered by BMW is staggered. I don't know why people buy an expensive M2 and then cheap out by getting a square setup for rotating.

https://www.shopbmwusa.com/Product/6...L-AND-TIRE-SET

https://www.shopbmwusa.com/PRODUCT/6...EL----TIRE-SET

https://www.shopbmwusa.com/PRODUCT/6...EL----TIRE-SET (note the 235 rear is a typo, it's 255 congruent with the 9" rear)

Like in warm weather even the non comp M2 struggles on 265 rears. A 235 rear winter tire seems basically insane IMO for dry cold weather driving. Plus it looks ridiculous unless you run spacers. And running spacers isn't that desirable in crap conditions.

[///M Houbi]

Originally Posted by mr_lab_rat

Guess what. My tire gauge was wrong! I thought I was running 35 but the actual pressure was 40PSI.

Bringing the pressure down to what it should be solved a lot of issues I had with my winter setup (high speed stability, low speed grip, twitchy steering).
Strange thing is that I used the same faulty tire gauge on my summer tires and they handled the extra pressure without too many problems.

Glad this fixed it!

I'm still amazed by the difference setting the correct pressure made...