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[asmazda]

Anybody here running 255/35/19 front and 285/30/19 or 295/30/19 rear on E9x M3? If yes, do you have any issues with DSC being too sensitive/engaging too early? Thanks in advance for your help!

[squartus]

Without euro MDM its far to sensitive period, that being said I cant say iv noticed it cutting in quicker with 275 up from 315 rear, or 255 front 305 rear.

[dmppdx]

The whole thing about changing tire size/ratio impacting the DCS has to be a urban legend. If a car is technological advanced enough to calculate it's geographic location to within a couple of meters using satellites in space, I'm pretty sure it is smart enough to calculate the relative rolling rotation of the tires and adjust accordingly. The M3 DSC is also expected to be used with a square set up since that is what BMW recommends for winter tires. It's probably the same programing used for other 3 serious which don't use a staggered set up also. I'm sure that BMW isn't going to hard code the ratio into the various version of the DSC software since would require they have a bunch of different version of the software to fit the different car and tire set ups.

[70X200]

Originally Posted by asmazda

Anybody here running 255/35/19 front and 285/30/19 or 295/30/19 rear on E9x M3? If yes, do you have any issues with DSC being too sensitive/engaging too early? Thanks in advance for your help!

I am running this same set up. No difference in DSC over stock set up. I would like to try the euro version some time.

[Dave07997S]

Ran this setup initially on my 2011 M3 and my 2013 M3, there is no issues with the DSC.

Dave

[asmazda]

Hi Dave, What are you running now and why did you change? Just to confirm, you were running 255/35 on the front and what size on the rear?

[bdaddylo]

Originally Posted by dmppdx

The whole thing about changing tire size/ratio impacting the DCS has to be a urban legend. If a car is technological advanced enough to calculate it's geographic location to within a couple of meters using satellites in space, I'm pretty sure it is smart enough to calculate the relative rolling rotation of the tires and adjust accordingly. The M3 DSC is also expected to be used with a square set up since that is what BMW recommends for winter tires. It's probably the same programing used for other 3 serious which don't use a staggered set up also. I'm sure that BMW isn't going to hard code the ratio into the various version of the DSC software since would require they have a bunch of different version of the software to fit the different car and tire set ups.

lol

I couldn't agree with you more.

[Dave07997S]

Originally Posted by asmazda

Hi Dave, What are you running now and why did you change? Just to confirm, you were running 255/35 on the front and what size on the rear?

I am running VMR V810 Flow Formed wheels in 19X10 and 19X11 with Mich PSS 275/30/19 and 295/30/19.



Here is the thread on them..

http://www.m3post.com/forums/showthread.php?t=1080173

[z3papa]

255/35-18F and 285/35-18R using RS3's -- no problem other than a little understeer at the extremes. Will go 275 square next.

[Dave07997S]

Originally Posted by z3papa

255/35-18F and 285/35-18R using RS3's -- no problem other than a little understeer at the extremes. Will go 275 square next.

the 255/35/18 is way to short for the front, that is only a 25" tall tire. OEM is 25.8", I wouldn't go below 25.5".

Dave

[z3papa]

It's shorter on both the front and the back intentionally. I guess you wouldn't suggest 285/30-18 squared but I've considered that as a setup.

[AlpGolcuklu]

I am using 255 front 285 rear. No problem with dsc. I always use dsc of haha

[dahherwang]

Originally Posted by Dave07997S

Ran this setup initially on my 2011 M3 and my 2013 M3, there is no issues with the DSC.

Dave

Hi Dave:
Sorry to bother you. I just bought a set of BBS RI-D rims, the width of RI-D for M3 is 9J(F)/10J(R). As you certainly know, 245/35/19 and 265/35/19 are definitely not the optimal choice for 9J and 10J rims due to the width difference between tire and rim. If you don't mind, would you please advise if the GTS size is still your best recommendation? Or you have any other thinking now? Thanks and best regards.

[Dave07997S]

Originally Posted by dahherwang

Hi Dave:
Sorry to bother you. I just bought a set of BBS RI-D rims, the width of RI-D for M3 is 9J(F)/10J(R). As you certainly know, 245/35/19 and 265/35/19 are definitely not the optimal choice for 9J and 10J rims due to the width difference between tire and rim. If you don't mind, would you please advise if the GTS size is still your best recommendation? Or you have any other thinking now? Thanks and best regards.

I think the GTS sizing is the best for this car with the 9 and 10 inch wide wheels. I know some will differ for going with a 275/35/19, which I think mainly is the fact that you can't get the Mich PSS in the 285/30/19 non RF in that size. I think the 245/265 size is to narrow.

Dave

[dahherwang]

Originally Posted by Dave07997S

I think the GTS sizing is the best for this car with the 9 and 10 inch wide wheels. I know some will differ for going with a 275/35/19, which I think mainly is the fact that you can't get the Mich PSS in the 285/30/19 non RF in that size. I think the 245/265 size is to narrow.

Dave

Hi Dave:
I just found that 285/30/19 is a rarely spec in Taiwan, tried my best but couldn't find any CSC5P even V105, only found P Zero and PS2(Yes, you haven't misread, made in 2014). P Zero and PS2, quite old design, which one will be your choice? Thanks and best regards.

[dahherwang]

Originally Posted by Dave07997S

I think mainly is the fact that you can't get the Mich PSS...

Dave

It's true, the same phenomenon in Taiwan. The enthusiastic people would rather change their tire size just because want to choose PSS rather than keeping the tire size but consider the other brands and models of tire....

[ben@tirerack]

Originally Posted by dmppdx

The whole thing about changing tire size/ratio impacting the DCS has to be a urban legend. If a car is technological advanced enough to calculate it's geographic location to within a couple of meters using satellites in space, I'm pretty sure it is smart enough to calculate the relative rolling rotation of the tires and adjust accordingly. The M3 DSC is also expected to be used with a square set up since that is what BMW recommends for winter tires. It's probably the same programing used for other 3 serious which don't use a staggered set up also. I'm sure that BMW isn't going to hard code the ratio into the various version of the DSC software since would require they have a bunch of different version of the software to fit the different car and tire set ups.

For the OP: 255/35R18 and 285/30R18 has been used pretty frequently, and I have not heard any problems with it. At this point it seems safe to say you'll be fine.

In regard to whether tire diameter can possibly affect the operation of traction control or stability control systems, it's certainly not a myth. I've known of cases where it has been a serious issue.

But in the case of the M3, the system has been found to work acceptably for pretty much any reasonable tire setup on the car. However, assuming that just because a car has GPS that it will recalibrate everything to whatever rolling diameter tire is on the car is a huge leap of faith, and not one for which I have seen any actual documentation.

[dmppdx]

Originally Posted by ben@tirerack

For the OP: 255/35R18 and 285/30R18 has been used pretty frequently, and I have not heard any problems with it. At this point it seems safe to say you'll be fine.

In regard to whether tire diameter can possibly affect the operation of traction control or stability control systems, it's certainly not a myth. I've known of cases where it has been a serious issue.

But in the case of the M3, the system has been found to work acceptably for pretty much any reasonable tire setup on the car. However, assuming that just because a car has GPS that it will recalibrate everything to whatever rolling diameter tire is on the car is a huge leap of faith, and not one for which I have seen any actual documentation.

I wasn't trying to imply there was connections between the GPS system and the traction control system, just that cars made now, unlike cars even made 10-15 years ago, are extremely computerized and sophisticated so there is no technological reason why a car couldn't be designed to compensate between square and staggered tires for a traction control system.

In fact, I really doubt the is a connection between the GPS system and the traction control system. It would be much better to design a car that automatically calibrates in the first few dozen feet that it is driven each time so that is knows the "normal" rotating relationship between the front and rear tires and uses that relationship in the calculations for the traction control.

[Dave07997S]

Originally Posted by dahherwang

Hi Dave:
I just found that 285/30/19 is a rarely spec in Taiwan, tried my best but couldn't find any CSC5P even V105, only found P Zero and PS2(Yes, you haven't misread, made in 2014). P Zero and PS2, quite old design, which one will be your choice? Thanks and best regards.

The summer Pzero is a very good tire, just awful tire wear. They can also get noisy when nearing the end of their life. The PZero is also a OEM tire for the M3.

Dave

[ben@tirerack]

Originally Posted by dmppdx

I wasn't trying to imply there was connections between the GPS system and the traction control system, just that cars made now, unlike cars even made 10-15 years ago, are extremely computerized and sophisticated so there is no technological reason why a car couldn't be designed to compensate between square and staggered tires for a traction control system.

In fact, I really doubt the is a connection between the GPS system and the traction control system. It would be much better to design a car that automatically calibrates in the first few dozen feet that it is driven each time so that is knows the "normal" rotating relationship between the front and rear tires and uses that relationship in the calculations for the traction control.

OK sorry, I thought that was what you were implying since you mentioned the GPS system, and that would actually be a somewhat logical way for the car to 'know' if the wheel diameter changed.

[Dave07997S]

For the OP: 255/35R19 and 285/30R19 has been used pretty frequently,

Fixed for you Ben..

[dahherwang]

After did a search in forum, I found that most of members here choose 255/275 and 265/295 rather than 255/285...I am curious about the main reason of this phenomenon, does it really cause by the overall diameter difference? Or simply because 285/30/19 is still not prepared by Michelin PSS?

On the other hand, almost all models of BMW cars have bigger front wheels than the rear(diameter), the familier difference is around 4.5~8.5mm, but M3(from E90/92) seems to be the only exception(rear bigger than front), is anyone know the reason why? Thanks and best regards.