[WaMi]

Originally Posted by Pol

Disadvantage of the 640M's, they are must heavier than the 437M's or the Apex.

Apex : 18x9 - 21,25 lbs (9,63kg)
BMW 437M : 19x9 - 22,04 lbs (10kg)
19x10 - 23,58 lbs (10,70kg)
BMW 640M : 18x8,5 - 24,84 lbs (11,270kg)
18x9 - 26,23 lbs (11,900kg)

You are awesome! Was literally just trying to look up the weight info as I'm on the fence between the BBS SR at 26 lbs, the 640m (I didn't know the weight), and the Apex at 21.25. Thank you!

[CAVU]

Originally Posted by Ex-MINI

Yes, it would be .4" wider at the front than stock. I took a chance and purchased a basically new OEM M3/M4 set from a forum member who sold his car. Haven't done a fitment test yet, but crossing my fingers that it should fit fine.

I'm hearing that the reason the BMW-recommended winterset for the F87 isn't square isn't a fitment issue, it's that the M2's DTC and DSC systems don't like a square setup. The last thing I need is my car to be pulling power or dragging brakes all winter. I may sell my F80 set and fall in line with BMW's recommended F87 set.

Does anybody know for sure how well the M2's DTC and DSC systems can cope with a square setup?

[Ex-MINI]

Originally Posted by CAVU

I'm hearing that the reason the BMW-recommended winterset for the F87 isn't square isn't a fitment issue, it's that the M2's DTC and DSC systems don't like a square setup. The last thing I need is my car to be pulling power or dragging brakes all winter. I may sell my F80 set and fall in line with BMW's recommended F87 set.

Does anybody know for sure how well the M2's DTC and DSC systems can cope with a square setup?

Where did you hear that? I find it a little hard to believe, as I know lots of folks who run a square setup on the track, and would obv have an issue if this was the case

[quikM2]

I really hope not as Apex just sold a huge junk of square set ups for winter to M2/3/4 owners. I can't imagine the computer can't handle a slight change in diameter and width. People change rims all the time and with that is sometimes dramatic changes in height and width and most importantly weight. Doesn't make sense.

[voinea]

Originally Posted by CAVU

I'm hearing that the reason the BMW-recommended winterset for the F87 isn't square isn't a fitment issue, it's that the M2's DTC and DSC systems don't like a square setup. The last thing I need is my car to be pulling power or dragging brakes all winter. I may sell my F80 set and fall in line with BMW's recommended F87 set.

Does anybody know for sure how well the M2's DTC and DSC systems can cope with a square setup?

exactly my thoughts ! That is why I also ordered the 640M F87 recommendation from leebmann24 website

[CAVU]

Originally Posted by Ex-MINI

Where did you hear that? I find it a little hard to believe, as I know lots of folks who run a square setup on the track, and would obv have an issue if this was the case

I'm with you, and I already put my money where my mouth is by buying a square F80 winterset. I'm still 99% sure I won't have an issue, but would like to know for sure. I may end up swapping wheels a week or two early just to do some testing.

I suspect that most people who run a square setup at the track do so with DTC/DSC off, so if there was an issue, it wouldn't show up there.

Here are a couple of posts I've read on the topic, which triggered my OCD:

http://f87.bimmerpost.com/forums/sho...20&postcount=9

http://f87.bimmerpost.com/forums/sho...32&postcount=8

[mfritz]

I spoke to tire rack about a square setup for winter wheels and they thought there could be an issue with traction control ( DSC and DTC). In there winter wheel configurator only a mixed 19 setup was an option. I went with 640M 18 inch staggered setup to be sure. It's a shame tire rack could not give us a definitive answer on this forum. It's too late for me but it would have been nice to know the options.

[voinea]

OZ Racing Italy also could not provide 100% sure answer. They only know that 9,5x18 OZ CHALLENGE HLT ET33 will work on the car. No other from them and they also not sure about tires ...
640M 8.5J + 9J with 235/40R18 & 255/35R18 seem 100% best option and the only factory approved now (except of 19" OEM)

[QM]

Originally Posted by CAVU

I'm with you, and I already put my money where my mouth is by buying a square F80 winterset. I'm still 99% sure I won't have an issue, but would like to know for sure. I may end up swapping wheels a week or two early just to do some testing.

I suspect that most people who run a square setup at the track do so with DTC/DSC off, so if there was an issue, it wouldn't show up there.

Here are a couple of posts I've read on the topic, which triggered my OCD:

http://f87.bimmerpost.com/forums/sho...20&postcount=9

http://f87.bimmerpost.com/forums/sho...32&postcount=8

I posted your question for Apex in the group buy thread.

[Japper69]

Originally Posted by QM

I posted your question for Apex in the group buy thread.

Surely a square setup does not affect DTC / DSC systems. RealOEM lists a 255 square setup on the 641 rims for the M3 /M4

[QM]

Originally Posted by Japper69

Surely a square setup does not affect DTC / DSC systems. RealOEM lists a 255 square setup on the 641 rims for the M3 /M4

That's what I'm hoping to hear and it does make sense that a square setup with same wheel diameter front and back would actually be the best case scenario for DTC/DSC with some threshold built in for different diameters in staggered setups.

[quikM2]

Anybody with more clarification on this issue? I ordered the square Apex setup at 18x9 +31 with 245/40 all around. I'm wondering if I should change this to the 235/40 and 255/35 people are referencing as the staggered option. In their writeup Apex talks about square being their reccomended fitment although that seems copied and pasted throughout for every version of the F8X and Ex M2/3/4 etc. so not sure if thats actually based on anything.

[Pol]

Originally Posted by quikM2

Anybody with more clarification on this issue? I ordered the square Apex setup at 18x9 +31 with 245/40 all around. I'm wondering if I should change this to the 235/40 and 255/35 people are referencing as the staggered option. In their writeup Apex talks about square being their reccomended fitment although that seems copied and pasted throughout for every version of the F8X and Ex M2/3/4 etc. so not sure if thats actually based on anything.

I conclude that on the German BMW forum www.1erforum.de, people in general adhere to the BMW requirements and go for 4x18x235/40 when winter chains are necessary or 2x18x235/40 and 2x18x255/35 in other circumstances.

[voinea]

You are right. On leebmann24 they say "mit gleicher Bereifung - 235/40 R18 95V vorne und hinten (Schneekettentauglich)" = with the same tires - 235/40 R18 95V front and rear (snow chain possible)

So this must be true. It is allow to have square setup . But still looks better with front 235/40 R18 95V, 255/35 R18 94V rear

[flyaway]

Originally Posted by Pol

In areas where snow is by times abundant, the 235's are a better option. BMW is a German car producer and usually they have relatively much snow during winter in most regions. For those areas with no or less snow the 255's in the rear are the better option as from tempatures beneath the 7°

+1

But personally I don't see the point in insisting driving the M2 in harsh winter conditions (and having the square setup). It's not that you can not do it, it just doesn't make sense.

[quikM2]

Originally Posted by flyaway

+1

But personally I don't see the point in insisting driving the M2 in harsh winter conditions (and having the square setup). It's not that you can not do it, it just doesn't make sense.

Not sure I understand what you're saying - What doesn't make sense? driving the M2 in winter at all, or driving the M2 on 10mm more width in the rear with a smaller sidewall?

[flyaway]

Originally Posted by quikM2

Not sure I understand what you're saying - What doesn't make sense? driving the M2 in winter at all, or driving the M2 on 10mm more width in the rear with a smaller sidewall?

Winter is a very different notion, depending on location... I can see the point of using a staggered winter set-up for temperatures bellow 7 deg C, in the mild winters we have in this part of Europe. But driving on regular basis in the snow (and needing thinner, square set up, tires) doesn't make much sense to me, in a M2 anyway. Just my 2c

[quikM2]

Originally Posted by flyaway

Winter is a very different notion, depending on location... I can see the point of using a staggered winter set-up for temperatures bellow 7 deg C, in the mild winters we have in this part of Europe. But driving on regular basis in the snow (and needing thinner, square set up, tires) doesn't make much sense to me, in a M2 anyway. Just my 2c

Well if that's how everyone felt there would be no M cars in a big chunk of the world. Where I am from in Canada it might be more on the extreme side with 4 months of -10 to -25 Celsius and snow and ice but I don't see why it wouldn't make sense in a city environment alongside countless M3/4/5/6's that have been doing it for a number of years on good winter tires. A lot of places in the states and in Finland, Sweden etc. etc. also face the same challenges and you rarely if ever hear anyone complain about their M car in the winter. So to be honest I still have to respectfully say i don't get your point. going from 255/35/18 in the rear to 245/40/18 is basically irrelevant.. what doesn't make sense in such a negligible situation?

[doug_999]

FYI - if you guys size out the tires (meaning see exactly how big they are in terms of diameter), you will see the actual issue is with the fronts not the rears (compared to stock).

Anyway, my point here is, BMW supports (and I believe recommends) the square setup. The wider rears are an option, and apparently the only one my dealer could find.

Originally Posted by flyaway

Winter is a very different notion, depending on location... I can see the point of using a staggered winter set-up for temperatures bellow 7 deg C, in the mild winters we have in this part of Europe. But driving on regular basis in the snow (and needing thinner, square set up, tires) doesn't make much sense to me, in a M2 anyway. Just my 2c

There really is no good reason to have a wider tire in the winter if you are driving in snow/ice.

[flyaway]

Originally Posted by quikM2

Well if that's how everyone felt there would be no M cars in a big chunk of the world. Where I am from in Canada it might be more on the extreme side with 4 months of -10 to -25 Celsius and snow and ice but I don't see why it wouldn't make sense in a city environment alongside countless M3/4/5/6's that have been doing it for a number of years on good winter tires. A lot of places in the states and in Finland, Sweden etc. etc. also face the same challenges and you rarely if ever hear anyone complain about their M car in the winter. So to be honest I still have to respectfully say i don't get your point. going from 255/35/18 in the rear to 245/40/18 is basically irrelevant.. what doesn't make sense in such a negligible situation?

Well, enjoy your M car in the winter then, no problem with me. I've just stated my opinion, based on my actual experience and nostalgically remembering the good times when I was thinking like you

[Wickedly]

Just curious where everyone is buying the oem wheels ? Are people just calling and ordering from their dealers ?

[doug_999]

Originally Posted by Wickedly

Just curious where everyone is buying the oem wheels ? Are people just calling and ordering from their dealers ?

Yep- There is not a ton of profit in the the wheel/tire combo. See if they will split it with you?