[ponykid]

Hi guys, I have a 2018 340 iXdrive with stock adaptive M chassis. Current staggered setup for summer 225/40R19 with 8'' ET 36 front and 255/35R19 with 8.5'' ET 47 rear. Now it's time to consider winter setup. A local guy has a square winter set for sell: 255/35R19 with 8.5'' ET35 off his 2016 M4. Not sure for any issue to put on my 340, especially the front.

I know this kind of questions had been asked almost every year around this time. Did some search but most OPs had lowed their suspension and mine is stock.

Appreciated for any advice given!

[Korvo]

Originally Posted by ponykid

Hi guys, I have a 2018 340 iXdrive with stock adaptive M chassis. Current staggered setup for summer 225/40R19 with 8'' ET 36 front and 255/35R19 with 8.5'' ET 47 rear. Now it's time to consider winter setup. A local guy has a square winter set for sell: 255/35R19 with 8.5'' ET35 off his 2016 M4. Not sure for any issue to put on my 340, especially the front.

I know this kind of questions had been asked almost every year around this time. Did some search but most OPs had lowed their suspension and mine is stock.

Appreciated for any advice given!

https://www.willtheyfit.com/

I found this site very helpful. I used it, this morning, to determine that a set of CL wheels would not fit my car. You need to make sure that "poke" isn't too far off and that the wheels will fit the strut. People running spacers (on 400M's) are using 18x8 ET34 with a 10mm spacer (simulating ET24) in the front. In the rear, 18x8.5 ET47 with a 15mm spacer (simulating ET32). The 1/2" rim width difference accounts for the ET difference between front and rear. You'll have to do the calculations with 19" wheels, but the calculator makes it easy.

For reference, most people running 19" VMR's are using ET35 all around. I was quoted recently and they suggested to do 19x8.5 ET35 front and 19x9.5 ET40 rear.

I'm not giving you a definite answer, because I don't want to be responsible for fitment issues. But.... I think the rears would fit perfectly, while the fronts would need a small spacer to be "flush".

[Billfitz]

You're begging for pothole damage to both tires and wheels with a 35 aspect ratio tire. Also, the wider the tire the less traction you have in snow and slush. You should be looking at 18s with 225/45.

[maku]

Originally Posted by ponykid

Hi guys, I have a 2018 340 iXdrive with stock adaptive M chassis. Current staggered setup for summer 225/40R19 with 8'' ET 36 front and 255/35R19 with 8.5'' ET 47 rear. Now it's time to consider winter setup. A local guy has a square winter set for sell: 255/35R19 with 8.5'' ET35 off his 2016 M4. Not sure for any issue to put on my 340, especially the front.

I know this kind of questions had been asked almost every year around this time. Did some search but most OPs had lowed their suspension and mine is stock.

Appreciated for any advice given!

I also have 340i XDrive with stock adaptive M chassis.
My winter set of wheels is:
8Jx18 ET34 225x45 R18 (all wheels are the same)

Indicated set of wheels (255/35R19 with 8.5'' ET35) it will fit, but such a width of tires will be less secure

[Sportstick]

Originally Posted by Billfitz

You're begging for pothole damage to both tires and wheels with a 35 aspect ratio tire. Also, the wider the tire the less traction you have in snow and slush. You should be looking at 18s with 225/45.

Agree. For winter time in Canada, the question is what studless winter (not performance winter) tires can you find in the narrowest width with enough capacity to hold your car's weight. Drive carefully for the hell months and wait for Spring! Study tirerack.com for answers.

[ponykid]

Thanks guys for the reply. I also tried on WillTheyFit but it only tells how much the new setup will be closer to the strut or how much it will pock out. It won't say if it fits for any particular vehicle. I know 225/45R18 maybe the best config for winter, safety and comfort wise. Still considering between these two options. My daily commute is very short and in town and no intention to drive crazy during winter.

[Sportstick]

Originally Posted by ponykid

Thanks guys for the reply. I also tried on WillTheyFit but it only tells how much the new setup will be closer to the strut or how much it will pock out. It won't say if it fits for any particular vehicle. I know 225/45R18 maybe the best config for winter, safety and comfort wise. Still considering between these two options. My daily commute is very short and in town and no intention to drive crazy during winter.

It's not about driving "crazy"...it's having the most traction capability to stop/turn when something unexpected slides in front of you when you've been driving responsibly.

[H2O]

Have the same car. My winter setup is square 245/40/18 michelin pa4 on oem 398 wheels and I have no complaint about it. Always felt safe in all the crazzy Quebec winter conditions. Actually I prefer this setup over my summer staggered 225/255 pss. Car is more balanced. I wonder if the 340 is not to powerfull to run on 225 winter square. It might lack of grip on a daily basis unless you use the eco mode for all winter.

[Sportstick]

Originally Posted by H2O

...I wonder if the 340 is not to powerfull to run on 225 winter square. It might lack of grip on a daily basis unless you use the eco mode for all winter.

35 mph is 35 mph regardless of having a 4 or 6 cylinder engine, and the rate of acceleration is totally controlled by the driver, so I question the premise of being too powerful for a 225 tire. The goal in winter is to have the narrowest tire which fits and has load capacity for the car. You have done well with the PA4, as it is not Michelin's most capable winter tire, which would be the XIcexi3. Hope they continue to serve you well if/when called upon for maximum stopping power on snow/ice.

[H2O]

Originally Posted by Sportstick

35 mph is 35 mph regardless of having a 4 or 6 cylinder engine, and the rate of acceleration is totally controlled by the driver, so I question the premise of being too powerful for a 225 tire. The goal in winter is to have the narrowest tire which fits and has load capacity for the car. You have done well with the PA4, as it is not Michelin's most capable winter tire, which would be the XIcexi3. Hope they continue to serve you well if/when called upon for maximum stopping power on snow/ice.

Originally Posted by Sportstick

35 mph is 35 mph regardless of having a 4 or 6 cylinder engine, and the rate of acceleration is totally controlled by the driver, so I question the premise of being too powerful for a 225 tire. The goal in winter is to have the narrowest tire which fits and has load capacity for the car. You have done well with the PA4, as it is not Michelin's most capable winter tire, which would be the XIcexi3. Hope they continue to serve you well if/when called upon for maximum stopping power on snow/ice.

Goal for maximum stopping power on any surface is to generate the more friction possible. Tire compound can only generate X amount of friction per unit of contact patch. The more contact patch the more friction can be used for stopping. Weight is only one factor that will bring your compound to its maximum friction temperature. More weight won't give more friction pass this maxima point. Goal is to find the widest tire that can be brought rapidly to maximum operating temperature. But wider is also more rolling resistance because of friction, which will impact gas consumption. Again it is all about compromise. I'm sure my stopping distance with 245 PA4 would be shorter than with 195 xicexi3 on snow. Maybe not on ice. Because tread design comes into play. Some tires are optimized for snow performance and some others for ice performance. Again compromise.

Stopping is one potentially hazardous driving condition. Breaking traction while accelerating is another one. This time torque comes into play. On slippery surfaces, the more torque the hardest to control the acceleration without breaking traction. It can rapidly become tricky when cornering. When I bought that nice Audi S4 V8, I thought it would be a blast in winter conditions over my A4. I was wrong. Was a lot easier and fun to drive and control the A4 in the snow. For the same reason, my old 2001 330xi is more fun to drive during winter snowfall than my 340xi.

Best advice is fore sure to adapt your driving to road condition, keep safe distance and anticipate for the worst.

[Sportstick]

Originally Posted by H2O

Goal for maximum stopping power on any surface is to generate the more friction possible. Tire compound can only generate X amount of friction per unit of contact patch. The more contact patch the more friction can be used for stopping. Weight is only one factor that will bring your compound to its maximum friction temperature. More weight won't give more friction pass this maxima point. Goal is to find the widest tire that can be brought rapidly to maximum operating temperature. But wider is also more rolling resistance because of friction, which will impact gas consumption. Again it is all about compromise. I'm sure my stopping distance with 245 PA4 would be shorter than with 195 xicexi3 on snow. Maybe not on ice. Because tread design comes into play. Some tires are optimized for snow performance and some others for ice performance. Again compromise.

Stopping is one potentially hazardous driving condition. Breaking traction while accelerating is another one. This time torque comes into play. On slippery surfaces, the more torque the hardest to control the acceleration without breaking traction. It can rapidly become tricky when cornering. When I bought that nice Audi S4 V8, I thought it would be a blast in winter conditions over my A4. I was wrong. Was a lot easier and fun to drive and control the A4 in the snow. For the same reason, my old 2001 330xi is more fun to drive during winter snowfall than my 340xi.

Best advice is fore sure to adapt your driving to road condition, keep safe distance and anticipate for the worst.

Respectfully, this could not be more wrong and defies physics. I suggest you and others interested do their own google searches to read widespread analyses of this topic, rather than take my word for it. Briefly, the value of the narrowest tire in winter is to increase the downforce psi to cut through snow. The simplest analogy is that a snowshoe distributes a pedestrian's weight to prevent sinking into the snow. The goal for a vehicle is to cut through the snow, not ride on top of it, and that occurs best with a constant mass on a narrower contact patch resulting in increased downforce psi. The narrower XIce xi3 will most definitely outperform your wider PA4 in all winter conditions, other than a dry and clear surface, both due to the narrower contact patch as well as the specifically designed chemistry of the softer compound.

Again, no point to further debate here. One can read about this from a variety of credible sources rather than anonymous forum members.

[H2O]

Originally Posted by Sportstick

Respectfully, this could not be more wrong and defies physics. I suggest you and others interested do their own google searches to read widespread analyses of this topic, rather than take my word for it. Briefly, the value of the narrowest tire in winter is to increase the downforce psi to cut through snow. The simplest analogy is that a snowshoe distributes a pedestrian's weight to prevent sinking into the snow. The goal for a vehicle is to cut through the snow, not ride on top of it, and that occurs best with a constant mass on a narrower contact patch resulting in increased downforce psi. The narrower XIce xi3 will most definitely outperform your wider PA4 in all winter conditions, other than a dry and clear surface, both due to the narrower contact patch as well as the specifically designed chemistry of the softer compound.

Again, no point to further debate here. One can read about this from a variety of credible sources rather than anonymous forum members.

Originally Posted by Sportstick

Respectfully, this could not be more wrong and defies physics. I suggest you and others interested do their own google searches to read widespread analyses of this topic, rather than take my word for it. Briefly, the value of the narrowest tire in winter is to increase the downforce psi to cut through snow. The simplest analogy is that a snowshoe distributes a pedestrian's weight to prevent sinking into the snow. The goal for a vehicle is to cut through the snow, not ride on top of it, and that occurs best with a constant mass on a narrower contact patch resulting in increased downforce psi. The narrower XIce xi3 will most definitely outperform your wider PA4 in all winter conditions, other than a dry and clear surface, both due to the narrower contact patch as well as the specifically designed chemistry of the softer compound.

Again, no point to further debate here. One can read about this from a variety of credible sources rather than anonymous forum members.

Respectfully either, I stand with my knowledge of physic engineering and how mathematics work. My point was that there is an optimal combination of many factors. Downforce psi being one of those factors that can have more or less importance depending on the road condition and targeted manoeuvre. Once asphalt is all cover with snow, there is one point where your tire will never cut deeply enough to reach asphalt. Compound is then less of a factor to stop the vehicle. What then takes the lead in stopping power is tread block design for scooping snow patches and it is the snow to snow contact that will create the friction to stop the vehicle. That is also well documented if one wants to google search. On ice, compound and micro-sipes to create suction must be optimized. Studs work even better to create friction. Road vehicle tires must have some competence in many aspect but at the end, it is always a compromise. That is why all seasons tires are just ok in all conditions but never outstanding in any conditions. Unfortunately, I never came across any scientific testing of the same tire model in different size (while keeping similar side wall ratio) on the same car and same road conditions (asphalt, snow, wet, ice). I bet it would show my point that optimal wide varies depending on surface condition and manoeuvre to perform. There is a point where you will loose performance going either to narrow or to wide. Until someone can point me to these kind of test data, I cannot scientifically presume that the narrower is better rule always overcome all the other factors on anything else than dry and clean conditions.

[Sportstick]

Originally Posted by H2O

Respectfully either, I stand with my knowledge of physic engineering and how mathematics work. My point was that there is an optimal combination of many factors. Downforce psi being one of those factors that can have more or less importance depending on the road condition and targeted manoeuvre. Once asphalt is all cover with snow, there is one point where your tire will never cut deeply enough to reach asphalt. Compound is then less of a factor to stop the vehicle. What then takes the lead in stopping power is tread block design for scooping snow patches and it is the snow to snow contact that will create the friction to stop the vehicle. That is also well documented if one wants to google search. On ice, compound and micro-sipes to create suction must be optimized. Studs work even better to create friction. Road vehicle tires must have some competence in many aspect but at the end, it is always a compromise. That is why all seasons tires are just ok in all conditions but never outstanding in any conditions. Unfortunately, I never came across any scientific testing of the same tire model in different size (while keeping similar side wall ratio) on the same car and same road conditions (asphalt, snow, wet, ice). I bet it would show my point that optimal wide varies depending on surface condition and manoeuvre to perform. There is a point where you will loose performance going either to narrow or to wide. Until someone can point me to these kind of test data, I cannot scientifically presume that the narrower is better rule always overcome all the other factors on anything else than dry and clean conditions.

We've now read both sides and appreciation that we did so civilly in this day and age! At this point, I don't think we can take it further here, but as noted, Google will be the friend of anyone who wants to do more research.

I'll try to help with a head start:

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

https://www.oponeo.co.uk/tyre-articl...res-for-winter

http://www.rimsandtiresmag.com/7-thi...s-narrow-tire/

https://resources.tireamerica.com/re...el-tireamerica

[H2O]

Originally Posted by Sportstick

We've now read both sides and appreciation that we did so civilly in this day and age! At this point, I don't think we can take it further here, but as noted, Google will be the friend of anyone who wants to do more research.

I'll try to help with a head start:

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

https://www.oponeo.co.uk/tyre-articl...res-for-winter

http://www.rimsandtiresmag.com/7-thi...s-narrow-tire/

https://resources.tireamerica.com/re...el-tireamerica

Originally Posted by Sportstick

We've now read both sides and appreciation that we did so civilly in this day and age! At this point, I don't think we can take it further here, but as noted, Google will be the friend of anyone who wants to do more research.

I'll try to help with a head start:

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

https://www.oponeo.co.uk/tyre-articl...res-for-winter

http://www.rimsandtiresmag.com/7-thi...s-narrow-tire/

https://resources.tireamerica.com/re...el-tireamerica

I agree, this debate has been instructive so far. I red all your proposed sourced with interest. Sadly we don't know much about the authors, there academic background nor there working experience. No doubt they must be car passionate but we almost all are on these forums. I don't see why one should consider them experts and believe everything they wrote. Most unfortunate, they don't give their sources and don't rely on any testing to prove their assumptions. They seem to propagate assumptions they heard and do make some sens because relying on simple single known scientific principle. It is pure oral tradition humanity is so good at. At one point in time, people thought earth was flat because the scientific principles they new at that time, which was very little, were guiding them to say so. If internet had existed in these days, google search would have been flooded with statements about earth being flat. Back to our contemporaneous authors, I did appreciate their effort to apply science to road phenomenon but it shows to the reading that they lack of scientific background to explain the more complexe situations, where the rubber meets the road! They oversimplified the studied conditions down to a single parameter so it can be explain with one scientific principle. Even then, some got confused with the selection of the principle to be applied to the described situation and contradict them-self to some point. At least one of them did recognize it was complexe and requires compromise. It is not that the science they rely to is not true, but it is the domain of applicability that is not always right. Newton classical mechanic laws are always true, but in the quantum mechanics domain, it is not precise enough to explain the phenomenon.

Nevertheless, I invite people interested in reading scientific literature about tire to subscribe to journals like this one:

http://tiresciencetechnology.org/doi...urnalCode=tist

Or if you want an overview of what can be found in those kind of publication, i found this for free:

https://vtechworks.lib.vt.edu/bitstr...pdf?sequence=1

[Solidjake]

OP, pass on those wheels. Look for 18's with as narrow tires as possible.