Help picking Tire size/stagger - MPS4S

[Mr. Hankey]

Hey All -

Would greatly appreciate help with tire sizing. What would you pick for MP4S tire sizing for daily driving, possible track day here and there? I thought I'd like #2 but the DSC thing worries me...want wider tires to help alleviate, not contribute, to the problem of rear grip!

EDIT for some background: I'm currently on 666M 265/285 30 R20 but going to wider lighter weight 19 inch 9.5 front, 10.5 rear rims. So already running the 285 MPSS out back, sounds like MP4S is a worthwhile upgrade. Not sure if a 295/30/19 out back with 1 inch wider contact patch than my current 285s will help a lot with grip or be barely noticeable. I'm aware of the issue with the 295/35/19 being narrower contact patch than the 285 in the MP4S.

1. 265/35/19 front (26.3 dia)
285/35/19 rear (26.9 dia)

2. 265/35/19 front (26.3 dia)
295/30/19 rear (26 dia, 1 inch wider contact over 285, but would DSC really intervene more with inverted diameters?)

3. 265/35/19 front (26.3 dia)
295/30/20 rear (27.0 dia) - wheels 2# heavier each

Thanks

[Pic18]

I personally would go with option 1

[wsccsw13]

Originally Posted by rhk118

Hey All -

Would greatly appreciate help with tire sizing. What would you pick for MP4S tire sizing for daily driving, possible track day here and there? I thought I'd like #2 but the DSC thing worries me...want wider tires to help alleviate, not contribute, to the problem of rear grip!

1. 265/35/19 front (26.3 dia)
285/35/19 rear (26.9 dia)

2. 265/35/19 front (26.3 dia)
295/30/19 rear (26 dia, 1 inch wider contact over 285, but would DSC really intervene more with inverted diameters?)

3. 265/35/19 front (26.3 dia)
295/30/20 rear (27.0 dia) - wheels 2# heavier each

Thanks

DSC adapts per Bosch who developed the system with BMW and make it for them; this came up in another thread and I contacted them directly for a definitive answer. The reply:

Dear Mr. ____,

Thank you for your question and interest in our mobility solutions.

The dynamic stability control is very robust, which means that it can cope with all approved tire combinations. Any measurable differences in the tire circumference are detected and compensated by the system. The angular speed of the wheel is corrected without any changes in the application parameter.
Mit freundlichen Grüßen / Best regards

I personally run staggered on the street and square on the track.

[Mr. Hankey]

Originally Posted by wsccsw13

DSC adapts per Bosch who developed the system with BMW and make it for them; this came up in another thread and I contacted them directly for a definitive answer. The reply:

Dear Mr. ____,

Thank you for your question and interest in our mobility solutions.

The dynamic stability control is very robust, which means that it can cope with all approved tire combinations. Any measurable differences in the tire circumference are detected and compensated by the system. The angular speed of the wheel is corrected without any changes in the application parameter.
Mit freundlichen Grüßen / Best regards

I personally run staggered on the street and square on the track.

That is great information. I imagine DSC must have some way to adapt to changing circumstances like changing tire pressures and wear front to back. So can't imagine a 0.3 inch smaller diameter out back would really mess with DSC but there are people out there who know a lot more about this than me who say it seems to intervene more with smaller diameter out back.

[Mr. Hankey]

Posted this elsewhere, but maybe this table will be helpful to someone regarding weights and tire sizes for MPSS and MP4S. Right column shows differences in tread width, diameter, sidewall height, and total tire/wheel weight not including weights or TPMS...please forgive the OCD...its my private "obsession"...may not be a fart smeller but dad jokes are my 2nd obsession.

[Signature Wheel BMW]

The answer depends, what is the offset of your new wheels? What suspension setup?

265/35 front and 285/35 rear

-OR-

265/35 front and 295/35 rear will work (not 295/30)

[Mr. Hankey]

Originally Posted by Signature Wheel BMW

The answer depends, what is the offset of your new wheels? What suspension setup?

265/35 front and 285/35 rear

-OR-

265/35 front and 295/35 rear will work (not 295/30)

Hey Jimmy - looking at et22 9.5 wide front, et35 10.5 rear - Just using FI-R as an example because I think their offsets look pretty good on the F80 and I would like to ditch spacers. Lowered on MP HAS. I would like more rubber out back than the 666s I'm running now with 285.

The MP4S are weird as you probably know. So with those offsets 265/35/19 front is likely going to be the tire. 295/35/19 rear is narrower than the 285/35/19...so its either 295/30/19 or 305/30/19 out back...and a bit worried about that much width out back with the 305 and rubbing with the MP HAS.

Others have suggested run the 265/30/19 up front with the 295/30/19 out back. And honestly if I went with MPSS could do 265/295/35 no problem likely. Continental could probably also run in a 265/295/35.

Apparently lots of people run the 265/35 and 295/30 out back in 19s but haven't found any direct reports on here regarding interference with TC. Appreciate any help.

[melanthius]

Running 275/30/19 and 305/30/19 no issues - could be a useful frame of reference for you.

It seems as long as the rear is a bit taller than the front you are good to go with these cars, and a lot of people report square setups without issues as well.

[Signature Wheel BMW]

Originally Posted by rhk118

Hey Jimmy - looking at et22 9.5 wide front, et35 10.5 rear - Just using FI-R as an example because I think their offsets look pretty good on the F80 and I would like to ditch spacers. Lowered on MP HAS. I would like more rubber out back than the 666s I'm running now with 285.

The MP4S are weird as you probably know. So with those offsets 265/35/19 front is likely going to be the tire. 295/35/19 rear is narrower than the 285/35/19...so its either 295/30/19 or 305/30/19 out back...and a bit worried about that much width out back with the 305 and rubbing with the MP HAS.

Others have suggested run the 265/30/19 up front with the 295/30/19 out back. And honestly if I went with MPSS could do 265/295/35 no problem likely. Continental could probably also run in a 265/295/35.

Apparently lots of people run the 265/35 and 295/30 out back in 19s but haven't found any direct reports on here regarding interference with TC. Appreciate any help.

265/35/19 front and 295/35/19 would be best. Keep in mind going from 295/35/19 to 305/30/19 doesn't mean more traction, more sidewall helps with the bite as much as width.

[M78W]

[/QUOTE]

Originally Posted by Signature Wheel BMW

The answer depends, what is the offset of your new wheels? What suspension setup?

265/35 front and 285/35 rear

-OR-

265/35 front and 295/35 rear will work (not 295/30)

I'm currently running 295/30/19 in the rear with MPSC2's

[Signature Wheel BMW]

Originally Posted by M78W

I'm currently running 295/30/19 in the rear with MPSC2's

Is there a reason why you didn't go with 295/35/19 instead?

Two setups below that's most common, we've done hundreds of set and collected data.

First is M4 GTS with Hoosiers 265/35/19 front and 295/35/19 rear. Second is M3 with RE-71R 265/35/19 front and 305/30/19 rear.

[Mr. Hankey]

Originally Posted by Signature Wheel BMW

Is there a reason why you didn't go with 295/35/19 instead?

Personally for me going to that 295/35/19 MP4S in Mercedes spec loses 1.2" of tread out back compared to the 295/30...yes I understand that the sidewall is more forgiving. Then the 285/35 becomes the better option with 10" of tread instead of the mercedes 295/35 which has 9.8 in of tread..

If upgrading rims to 19s (from 666m 20s) just based on measurements I'd probably be better staying with MPSS in the 265/35 and 295/35 and at least gain 0.5" of tread up front and out back...just would like the newer tech in the MP4S tires.

Jimmy - in the MP4S on a 19" rim is there a problem you see with 265/35 up front and 295/30 out back? It is something people are complaining about or having to change that rear tire size once they've been driving with it a while? I'd just like to know why you recommend against it...I know it may not be a common size combo you see people putting on M3/4s. I really appreciate your input.

Also nice pics!

[M78W]

Originally Posted by M78W

I'm currently running 295/30/19 in the rear with MPSC2's

Is there a reason why you didn't go with 295/35/19 instead?

Two setups below that's most common, we've done hundreds of set and collected data.

First is M4 GTS with Hoosiers 265/35/19 front and 295/35/19 rear. Second is M3 with RE-71R 265/35/19 front and 305/30/19 rear.[/QUOTE]

I wanted to get the most rubber on the road that I could with stock tires. I'm also running 265/30/19 in the front, I wish I went with a larger sidewall being in New England. I'm thinking about my next set of wheels and tires though. How large of a wheel can you put in the back before it becomes counter productive?

[Signature Wheel BMW]

Originally Posted by M78W

I wanted to get the most rubber on the road that I could with stock tires. I'm also running 265/30/19 in the front, I wish I went with a larger sidewall being in New England. I'm thinking about my next set of wheels and tires though. How large of a wheel can you put in the back before it becomes counter productive?

Gotcha, so you had 265/30 in front first and wanted 295/30 in the rear to match the OD ratio. 295/35/19 or 305/30/19 would the widest I'd go, anything past that just upgrade to better compound.

[M78W]

Originally Posted by Signature Wheel BMW

Gotcha, so you had 265/30 in front first and wanted 295/30 in the rear to match the OD ratio. 295/35/19 or 305/30/19 would the widest I'd go, anything past that just upgrade to better compound.

Originally Posted by Signature Wheel BMW

Gotcha, so you had 265/30 in front first and wanted 295/30 in the rear to match the OD ratio. 295/35/19 or 305/30/19 would the widest I'd go, anything past that just upgrade to better compound.

Is there anything better than pilot sport cup 2's though?

[Mr. Hankey]

Originally Posted by M78W

Is there anything better than pilot sport cup 2's though?

How do you deal with SC2s in Maine! Especially with all the rain...MPSS's are safely good down to about 24 degrees F I can tell you that...but PSC2? They must be like barbie mustang power wheels plastic tires! (just saying that because I might have 1)

I think above the PSC2s Toyo 888s might have more...but have never driven on them...

[M78W]

Originally Posted by rhk118

How do you deal with SC2s in Maine! Especially with all the rain...MPSS's are safely good down to about 24 degrees F I can tell you that...but PSC2? They must be like barbie mustang power wheels plastic tires! (just saying that because I might have 1)

I think above the PSC2s Toyo 888s might have more...but have never driven on them...

Lol I only run the car from May-october and it's usually 50 minimum. I can only imagine what the tires would fare

[Mr. Hankey]

Ok just some follow up in case anyone checks this in the future. I went with MP4S 265/35-19 in the front and 295/30-19 in the rear. Had them for a month now and about 600 miles. Grip is way better with MP4S than the MPSS. I imagine this is more due to the compound than the extra 10 mm out back. It's tough to spin the tires in second now (I'm not a clutch dropper but even with fast weight transfers they are hard to break free).

The dreaded overzealous DSC intervention has not been an issue at all for me with the 35 sidewall up front and the 30 out back. Running 36 psi out back, 33 psi up front. In fact DSC intervenes less. Maybe it's more grip where MPSSs would slide. MP4S feel like they have more sidewall flex in turns with bumps than the MPSSs (less stretched/more grip?) but I am taking some of my favorite turns faster now where I used to be able to slide a little (and kinda miss TBH). For that reason (getting into a little slide here and there) maybe 285/35-19 out back would have made the car feel more "normal" to me.

My Speedo reads about 1.5-2 MPH faster than GPS or radar clocked speeds as the only expected annoyance. In any event I'm very happy. Will see how these tires do once they've had a chance to really wear. Thanks all again for your help!

[CanAutM3]

Originally Posted by rhk118

Grip is way better with MP4S than the MPSS. I imagine this is more due to the compound than the extra 10 mm out back.

For sure, the more advance compound of the PS4S contributes to the increased grip, but note that the 295/30R19 PS4S has a whopping 36mm wider contact patch than the stock 275/35R19(*) PSS.

[Mr. Hankey]

Originally Posted by CanAutM3

For sure, the more advance compound of the PS4S contributes to the increased grip, but note that the 295/30R19 PS4S has a whopping 36mm wider contact patch than the stock 275/35R19(*) PSS.

Oh I noted that! The 295/35-19 had slightly less contact patch than the 285 MPSS which means maybe better hydroplaning resistance (i think Mercedes intended tire), but still likely better grip because of the newer compound. The 295/30 contact patch much wider than both. These things are planted...I can't imagine the grip you have with your 11" track setup.

MPSSs would slide fairly predictably. I haven't found that comfort zone with these just yet...concern is they will just break, even though i know that not to be true.

[kevin85]

Originally Posted by rhk118

Ok just some follow up in case anyone checks this in the future. I went with MP4S 265/35-19 in the front and 295/30-19 in the rear. Had them for a month now and about 600 miles. Grip is way better with MP4S than the MPSS. I imagine this is more due to the compound than the extra 10 mm out back. It's tough to spin the tires in second now (I'm not a clutch dropper but even with fast weight transfers they are hard to break free).

The dreaded overzealous DSC intervention has not been an issue at all for me with the 35 sidewall up front and the 30 out back. Running 36 psi out back, 33 psi up front. In fact DSC intervenes less. Maybe it's more grip where MPSSs would slide. MP4S feel like they have more sidewall flex in turns with bumps than the MPSSs (less stretched/more grip?) but I am taking some of my favorite turns faster now where I used to be able to slide a little (and kinda miss TBH). For that reason (getting into a little slide here and there) maybe 285/35-19 out back would have made the car feel more "normal" to me.

My Speedo reads about 1.5-2 MPH faster than GPS or radar clocked speeds as the only expected annoyance. In any event I'm very happy. Will see how these tires do once they've had a chance to really wear. Thanks all again for your help!

I'm looking at the same setup as yours, 265/35/19 in front and 295/30/19 in the rear. So, you have no DSC issue with the rear tire diameter being slightly smaller than the front, where the front used to be 0.6" smaller than the rear.

[Mr. Hankey]

Originally Posted by kevin85

I'm looking at the same setup as yours, 265/35/19 in front and 295/30/19 in the rear. So, you have no DSC issue with the rear tire diameter being slightly smaller than the front, where the front used to be 0.6" smaller than the rear.

I don't seem to at all. Traction is so much better though that limits are higher than what I'm used to. On the street its been absolutely planted and it actually seems harder to activate DSC (I use MDM all the time)...I'm also not tracking so maybe if setting lap times with DSC or MDM on it intervenes more, but I have been more than happy with this setup so far.