[Bimmr7]

Originally Posted by adc

My second F80 M3 had 265 at the front and i didn’t experience more aqua planing compared to my 2015 with 255 fronts.

Then when I switched to Michelin Pilot Sport 4S (an “upgrade” by all accounts compared to the OEM Pilot Super Sport) and i went with 275 fronts, I’m still ok.

So I doubt it will be a major factor. After all, they do have occasional rain in Germany.

Occasional rain? Try Oct-Dec and just about every other day.

[solstice]

Originally Posted by KoenG

Yes, when weight distribution between AWD versions are similar, and both use the same bias f/rwd and both have the same height of COG and share the same torsional stifness and have comparable wheelbase. But combine all this is exactly the job of Frank or not?

Right but the AWD G8X isn’t launched yet.

[KoenG]

Originally Posted by solstice

Right but the AWD G8X isn’t launched yet.

I presume that Frank has some experiences he couldn't share with us yet? Soon, it will clear up I hope? Since the vid clearly didn't.

[solstice]

Originally Posted by KoenG

I presume that Frank has some experiences he couldn't share with us yet? Soon, it will clear up I hope? Since the vid clearly didn't.

If the boss hasn’t lifted the internal only classification Frank better keep quite for now. Regarding AWD I also vaguely recall lemetier hinting that the AWD model contain another”Easter egg”. I.e. some new technical feature. I could have mixed that up though.

[mfurse]

Originally Posted by KoenG

So you believe that a car is only enjoyable in real life when its handling limits aren't that good? Maybe test a Porsche Turbo S then?

My point was that cars built to move about and provide lots of driver interaction are generally enjoyable at sensible road speeds and give you something to do - the 1M did this nicely.

There are a few cars that make themselves less interactive at lower speeds to focus on higher ultimate performance which can spoil them or make their control points seem "aloof" (i.e. some RS Audi's).

Porsche 911's are built on a custom platform so they have more control over both the low speed interactivity and the higher speed handling. I hope the M3 hasn't aimed at the higher speed/track times at the expense of the more accessible interactivity on the road.

Another member mentioned "today's E30 M3" is likely the GT86 and they could be right - small, light, interactive, small power, loves being revved out and enjoyable at road speeds.

I hope I'm wrong and the G8x nails the brief for all areas of driving but I'm predicting BMW have moved the needle on track times whilst making the car less fun on the road.

[maddmatth]

Originally Posted by sasa.baska

I wonder how will G80 drive in rain with 275 at front... with my F80 and 255 tire I have to reduce the speed a lot otherwise it aquaplans like crazy... def not confidence inspiring in rain

You must be doing some crazy speeds... up to about 120/130kph in heavy rain on country roads, I still felt like I had good grip. With the OEM PSS tyres.
Felt about as good as anything else I've driven.
That's 120/130 when overtaking, down to about 100 when cruising.

Would not risk higher speeds than that though, without an autobahn...

[sasa.baska]

Originally Posted by maddmatth

You must be doing some crazy speeds... up to about 120/130kph in heavy rain on country roads, I still felt like I had good grip. With the OEM PSS tyres.
Felt about as good as anything else I've driven.
That's 120/130 when overtaking, down to about 100 when cruising.

Would not risk higher speeds than that though, without an autobahn...

The problem is where the water runs across the road creating small (dont know how to say in english) "creaks"...It unsetless the car greatly, not to mention if It happens in turn It's even worse as loosing grip/aquaplans...but as you said, Up to 100-120 kmh It's ok...but hate to be amoungh the slowest cars on the road in such conditions...
and with 275 Up front on G80 It will be worse

[bm323]

We can’t compare whether aquaplaning is usual. It depends on the depth and length of the puddle. At 200 kmph in rain, there may be no aquaplaning vs aquaplaning is usual with PS4S in 100kmph over a deep and long puddle.

[2one3E90]

Lolol its funny cuz half of the owners are gonnna swap em out for toyo R888 or Hankook RS4s anyways. Those tires wont match the grip of these.

[NISFAN]

Originally Posted by bm323

We can't compare whether aquaplaning is usual. It depends on the depth and length of the puddle. At 200 kmph in rain, there may be no aquaplaning vs aquaplaning is usual with PS4S in 100kmph over a deep and long puddle.

You can work it out, it's simple physics using Pressure / area calculations. Wider tyres increase the area which has a profound effect on speed of aqua planing onset.

The more in depth calculation is the land to sea calculation of a particular tyre,(average tread width as a percentage). Also it's tread depth to determine how deep a puddle needs to be before grooves become ineffective. Tyre pressure has an effect too.

In simple terms, if the puddle is deep enough, and the force great enough (velocity and area) to support the axle weight, the tyre will depart from the road surface. Once this happens, tread design, rubber compound or any great technology built into the tyre to promote wet grip ceases to work.

Front tyre size is particularly important, as it is the axle that clears the water for the rears. Making the rear widths not as critical.

I would be very concerned about driving a 3 series size car with very worn front 275 section tyres at high speed in the rain. Very worn being <3.5mm tread depth across the whole tyre.

I am surprised about the MPC2 comments above. I have these on my M2C and manage to aqua plane regularly. Cup2's have a particularly wide outer shoulder (low Land to sea) with almost no drainage channels, and at best the tread depth is only 5.5mm (new). Not great anti aqua plane features.

Coming back on topic, IMO these minimal stagger, wide fronts was something I foresaw happening with the last generation cars and the creep of xDrive. To put it bluntly, there is significant cost involved in achieving a 50:50 balanced FR chassis. The fanaticism of that balance is only really worthwhile on a RWD platform. Once you transition to an AWD platform, the 50:50 balance characteristics moves down the list of importance.
Moving towards a square tyre fitment is IMO confirmation that this rot has set in. Counteracting under steer with tyre size not chassis balance. They foresee AWD will be the big seller, which makes a focussed (BMW roots) RWD chassis the niche.

Such a shame.

[CanAutM3]

Originally Posted by NISFAN

Once you transition to an AWD platform, the 50:50 balance characteristics moves down the list of importance.

First time I hear this. Could you expand as to why you believe this would be the case?

[NISFAN]

Originally Posted by CanAutM3

First time I hear this. Could you expand as to why you believe this would be the case?

BMW has for a long time aimed to achieve the nirvana of a 50:50 balance. I know you have been vocal about the 50:50 not evidenced at being the best, and I'd certainly agree it isn't the best balance for a car, mid engined sports cars have proven this. But on practical terms for an FR chassis (front engined, rear drive for those that are unfamiliar with the FR term), 50:50 is about as good as you can practically achieve. Even so it's not easy achieve, that's why Mercedes and others don't even bother. It costs BMW lots of money in weight engineering the crap out an FR to achieve this long standing benchmark and BMW tradition. This point is important.

In adding an AWD drivetrain we have introduced drive train drag and added weight to the front axle. Both of these increase under steer. How do we counter under steer? Increasing front axle grip. Viola, bigger section front tyres. You got it more front weight, and since you've increased the effectiveness of the front axle, the bigger brakes need to go here, more chassis rigidity here too, there are new forces on the front axles that we didn't have before. Incrementally the weight balance moves further and further forward and there is nothing you can do about it other than to embrace the fact that 50:50 is dead.

This leads to bean counters fighting back undoing all the expensive stuff you implemented to achieve "the BMW balance", because it's broken anyway and Audi do OK without. You've lost the anchor in the argument, that historical yardstick. It doesn't get replaced by 55:45, no it it just goes.

Oh and if you think that's OK, the RWD version will still be OK? Right? No, the whole platform has been compromised. Strut turrets, front geometry aimed to driven front axle inclinations. Wheel wells designed for wide (unnecessary) tyres, carrying big heavy brakes. Chassis strength focussed to adapt to AWD needs, the list goes on, but all at cross purpose to 50:50 balance. This is a real shift, the G20 340i is AWD only in many markets, this indicates the direction of chassis development for AWD. It ends in a video showing distorted weight difference between old and new and not a peep about weight distribution. Purposely omitted no doubt.

Coming back to your question, it is inevitable. There are only two manufacturers that I can recall having tried to control weight distribution on FAWD platforms. Subaru and Nissan GTR. One is a low volume super car with an expensive and unpractical transaxle gearbox, the other no longer bothers. A lost battle.

C'est la vie.

[solstice]

Originally Posted by NISFAN

BMW has for a long time aimed to achieve the nirvana of a 50:50 balance. I know you have been vocal about the 50:50 not evidenced at being the best, and I'd certainly agree it isn't the best balance for a car, mid engined sports cars have proven this. But on practical terms for an FR chassis (front engined, rear drive for those that are unfamiliar with the FR term), 50:50 is about as good as you can practically achieve. Even so it's not easy achieve, that's why Mercedes and others don't even bother. It costs BMW lots of money in weight engineering the crap out an FR to achieve this long standing benchmark and BMW tradition. This point is important.

In adding an AWD drivetrain we have introduced drive train drag and added weight to the front axle. Both of these increase under steer. How do we counter under steer? Increasing front axle grip. Viola, bigger section front tyres. You got it more front weight, and since you've increased the effectiveness of the front axle, the bigger brakes need to go here, more chassis rigidity here too, there are new forces on the front axles that we didn't have before. Incrementally the weight balance moves further and further forward and there is nothing you can do about it other than to embrace the fact that 50:50 is dead.

This leads to bean counters fighting back undoing all the expensive stuff you implemented to achieve "the BMW balance", because it's broken anyway and Audi do OK without. You've lost the anchor in the argument, that historical yardstick. It doesn't get replaced by 55:45, no it it just goes.

Oh and if you think that's OK, the RWD version will still be OK? Right? No, the whole platform has been compromised. Strut turrets, front geometry aimed to driven front axle inclinations. Wheel wells designed for wide (unnecessary) tyres, carrying big heavy brakes. Chassis strength focussed to adapt to AWD needs, the list goes on, but all at cross purpose to 50:50 balance. This is a real shift, the G20 340i is AWD only in many markets, this indicates the direction of chassis development for AWD. It ends in a video showing distorted weight difference between old and new and not a peep about weight distribution. Purposely omitted no doubt.

Coming back to your question, it is inevitable. There are only two manufacturers that I can recall having tried to control weight distribution on FAWD platforms. Subaru and Nissan GTR. One is a low volume super car with an expensive and unpractical transaxle gearbox, the other no longer bothers. A lost battle.

C'est la vie.

You do know that BMW’s 3 series platforms have offered AWD since the E30, right?

[M3AWD]

I can easily make my AWD G80 50/50 by adding sandbags in the trunk as needed

[PLF69]

[OG///M]

Originally Posted by NISFAN

BMW has for a long time aimed to achieve the nirvana of a 50:50 balance. I know you have been vocal about the 50:50 not evidenced at being the best, and I'd certainly agree it isn't the best balance for a car, mid engined sports cars have proven this. But on practical terms for an FR chassis (front engined, rear drive for those that are unfamiliar with the FR term), 50:50 is about as good as you can practically achieve. Even so it's not easy achieve, that's why Mercedes and others don't even bother. It costs BMW lots of money in weight engineering the crap out an FR to achieve this long standing benchmark and BMW tradition. This point is important.

In adding an AWD drivetrain we have introduced drive train drag and added weight to the front axle. Both of these increase under steer. How do we counter under steer? Increasing front axle grip. Viola, bigger section front tyres. You got it more front weight, and since you've increased the effectiveness of the front axle, the bigger brakes need to go here, more chassis rigidity here too, there are new forces on the front axles that we didn't have before. Incrementally the weight balance moves further and further forward and there is nothing you can do about it other than to embrace the fact that 50:50 is dead.

This leads to bean counters fighting back undoing all the expensive stuff you implemented to achieve "the BMW balance", because it's broken anyway and Audi do OK without. You've lost the anchor in the argument, that historical yardstick. It doesn't get replaced by 55:45, no it it just goes.

Oh and if you think that's OK, the RWD version will still be OK? Right? No, the whole platform has been compromised. Strut turrets, front geometry aimed to driven front axle inclinations. Wheel wells designed for wide (unnecessary) tyres, carrying big heavy brakes. Chassis strength focussed to adapt to AWD needs, the list goes on, but all at cross purpose to 50:50 balance. This is a real shift, the G20 340i is AWD only in many markets, this indicates the direction of chassis development for AWD. It ends in a video showing distorted weight difference between old and new and not a peep about weight distribution. Purposely omitted no doubt.

Coming back to your question, it is inevitable. There are only two manufacturers that I can recall having tried to control weight distribution on FAWD platforms. Subaru and Nissan GTR. One is a low volume super car with an expensive and unpractical transaxle gearbox, the other no longer bothers. A lost battle.

C'est la vie.

This is well written. Agree completely. Especially the part about achieving close to 50:50 as possible being difficult in an FR vehicle.

Just because 50:50 isn't better than a slight rear bias to begin with, doesn't mean 55:45 is now acceptable. It's actually worse than 50:50, magnitudes worse.

[NISFAN]

Originally Posted by solstice

You do know that BMW’s 3 series platforms have offered AWD since the E30, right?

Ah yes, the E30 competition - xDrive only. I remember it well

[ashtaron14]

The Q&A from Frank is out on Instagram
My question got answered

[SYT_Shadow]

I dislike AWD as much as any of you, but despite the theory you drive something like the M5c and it feels wonderful. I would still prefer RWD.

Even on the M3 forum it's chock full of people pining for AWD, I'm not surprised BMW offered it and I'm thankful they still offer a true RWD version for us.

AWD sells. One could say it sells to stupid people, but it sells nonetheless. 0-60 is all the rage for those cool youtube videos!

[1claire]

This is an interesting video about the tires that BMW use.

[maddmatth]

Originally Posted by ashtaron14

The Q&A from Frank is out on Instagram
My question got answered

Can't find it. Anyone able to link to it?

Not much of an Instagram user so maybe I'm just being a noob here. I could see the other videos but not an FAQ.

Edit, here: https://www.instagram.com/stories/bm...0487379786970/
What a godawful interface Instagram has.
Nothing much there, and repetitive questions about run flats and tyre pressure...

[Mospeada]

i use cup2 on my car and recently got 265/35 cup2 and saw that they have new DT1 (different tread 1) and tire rating of 240!!! that's crazy. and it's bmw star. i looked everywhere and found that 245/35 is also DT1 240 rating. so that's whats going to be on M2 wheels . i do not see 285/35 or 285/30 offered in DT1 yet. maybe they will. then i saw this vid and one of the large ass tire has to be 285 rear on this new M car. so that tells me 285 DT1 star rated tire is coming. i think it's awesome that cup2 is getting upgraded . i'm a big fan of cup2 and was going to switch to S007A, i prolly will anyway becuase of cost difference and so many tires i go through each year