BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
M2 Technical Topics > Wheels / Tires -- Sponsored by The Tire Rack > Can 4 PSI make that big of a difference?

Post Reply
 
Thread Tools Search this Thread
      08-01-2020, 03:19 PM   #1
cptobvious
Captain
cptobvious's Avatar
United_States
2532
Rep
825
Posts

Drives: M2C HS DCT
Join Date: Jul 2018
Location: San Diego, CA

iTrader: (0)

Can 4 PSI make that big of a difference?

Gentlemen (and I use the term loosely), wanted to get your thoughts and experiences with regard to tire pressure.

Recently changed my rear tires to General G-Max RS 275/35/19 from MPSS 265/35/19. Immediately felt like the car was unsettled and twitchy when pushed. Really, really did not like it at all. Thought, "Oh well, that's $340 wasted. Gotta go buy the MPS4S's now."

But, then, randomly did some reading online and came across several articles about tramlining and tire pressure - articles seemed to indicate that one way to potentially reduce the tramlining is with lower tire pressure.

https://www.tirerack.com/tires/tiret....jsp?techid=47

Sure enough, I checked my tire pressure, and the installers had it all the way up to 39 PSI. Brought the rears back down to 35 PSI, and all seems right with the world again.

It went from, "I can't stand these F***ing tires," to "Oh, gosh, daily driving, I can't tell the difference between these and the MPSS."

So, question for you all is: "Is this all just my imagination? Like, placebo effect? Or does 4 PSI make that much of a difference???"
Appreciate 0
      08-01-2020, 03:26 PM   #2
Brandt51
Flavor of the month
Brandt51's Avatar
838
Rep
689
Posts

Drives: BMW F87 M2C
Join Date: May 2019
Location: Not Sin City, Nevada

iTrader: (0)

Garage List
2020 BMW F87  [9.50]
I think so yes. Some are better at feeling a difference than others.
__________________
Samuel of the Internet
2023 F98 X4M Comp
2023 F95 X5M Comp
2020 F87 M2 Comp
Appreciate 1
cptobvious2531.50
      08-01-2020, 03:26 PM   #3
ChrisK
Major General
ChrisK's Avatar
United_States
4449
Rep
7,594
Posts

Drives: '19 M2C
Join Date: Jun 2007
Location: Chicagoland

iTrader: (7)

Garage List
Absolutely. 4 PSI can make the world difference.
__________________
www.ReTuneTheDeTune.com
2019 M2 Competition (Sunset Orange)
Appreciate 2
cptobvious2531.50
Tag17910.00
      08-01-2020, 03:50 PM   #4
Tag
this is the way
Tag's Avatar
17910
Rep
8,457
Posts

Drives: N-1 starfighter
Join Date: Jan 2007
Location: Chicago

iTrader: (3)

Yes, it makes a difference. Just like not having four MPS4S makes a difference.

This makes me wonder why you didn't consult your brethren before purchasing tires? Don't you trust us, impulse buying at the local Walmart, honeymoon with the car over, sleep walking... again, covid brain fog, ate too much cap'n crunch, cptobvious?
Appreciate 6
cptobvious2531.50
ChrisK4449.00
Bobh5952.00
///AVM2528.00
KevinM2931.00
Davil6332.00
      08-01-2020, 03:56 PM   #5
VisualEcho
Banned
VisualEcho's Avatar
United_States
6626
Rep
4,145
Posts

Drives: '18 M2 6MT
Join Date: Sep 2019
Location: Missouri

iTrader: (1)

Garage List
2018 BMW M2  [10.00]
Yes, it can, and the LIGHTER the car, the more the difference. I once had an installer put 35/35 in my Exige tires that should be 23/25 and the entire ride home I thought the car was trying to kill me. I'm surprised I kept it on the road. Lowering the pressure turned it right back into a go-kart, instantly.
Appreciate 2
cptobvious2531.50
///AVM2528.00
      08-01-2020, 04:16 PM   #6
Mavus
Colonel
Mavus's Avatar
2015
Rep
2,659
Posts

Drives: E90 335i, F80 zcp
Join Date: Sep 2011
Location: PA

iTrader: (9)

yes that is a significant defference and you can feel it if you push it even a little bit. The chassis will communicate to your ass.
Appreciate 1
cptobvious2531.50
      08-01-2020, 04:33 PM   #7
BigKutta
Brigadier General
BigKutta's Avatar
United_States
3871
Rep
4,040
Posts

Drives: 2020 M2C, 2019 330xi, 2017 Q7
Join Date: Jan 2012
Location: Washington DC Burbs

iTrader: (1)

Garage List
2019 330xi  [0.00]
2017 Audi Q7 3.0  [0.00]
2020 M2C  [0.00]
Yes, absolutely. I can tell when my tires lose pressure, it drives differently. And usually when I check, its off by 4-5 psi
Appreciate 1
cptobvious2531.50
      08-01-2020, 05:51 PM   #8
cptobvious
Captain
cptobvious's Avatar
United_States
2532
Rep
825
Posts

Drives: M2C HS DCT
Join Date: Jul 2018
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by Tag View Post
Yes, it makes a difference. Just like not having four MPS4S makes a difference.

This makes me wonder why you didn't consult your brethren before purchasing tires? Don't you trust us, impulse buying at the local Walmart, honeymoon with the car over, sleep walking... again, covid brain fog, ate too much cap'n crunch, cptobvious?

Too funny!

Since you're giving me stick, here was my rationale:

1. Rear tires wore out, but my front tires are still in really good shape
2. Also, wanted to play around with tire size
3. If I experimented with MPS4S's, that would have cost me ~$640 + tax
4. So, instead, decided to experiment with the General tires, and they only cost ~$340 + tax
5. I think I've come to the conclusion that I prefer OEM sizing - figure the engineers knew what they were doing with regard to vehicle dynamics, so why gainsay them?
6. Now, plan is when the front tires wear out, I'll get all 4 MPS4S's OEM size, having conducted my experiment to my satisfaction

Come on! I'm a man with a plan!
Appreciate 2
Tag17910.00
Brandt51838.00
      08-01-2020, 05:52 PM   #9
omasou
Colonel
omasou's Avatar
United_States
2080
Rep
2,999
Posts

Drives: BMWs
Join Date: Apr 2016
Location: US

iTrader: (4)

Garage List
2023 BMW S1000RR  [0.50]
2022 BMW F900XR  [3.00]
2022 BMW X6 40i  [0.50]
2020 BMW M2C  [9.50]
So this begs the question.

What tire brand, F&R size and pressures are you running?

Maybe, I should change?

MPSS 245/265 35/35 per jamb sticker.

Last edited by omasou; 08-01-2020 at 06:14 PM..
Appreciate 0
      08-01-2020, 05:53 PM   #10
omasou
Colonel
omasou's Avatar
United_States
2080
Rep
2,999
Posts

Drives: BMWs
Join Date: Apr 2016
Location: US

iTrader: (4)

Garage List
2023 BMW S1000RR  [0.50]
2022 BMW F900XR  [3.00]
2022 BMW X6 40i  [0.50]
2020 BMW M2C  [9.50]
Quote:
Originally Posted by cptobvious View Post
Too funny!

Since you're giving me stick, here was my rationale:

1. Rear tires wore out, but my front tires are still in really good shape
2. Also, wanted to play around with tire size
3. If I experimented with MPS4S's, that would have cost me ~$640 + tax
4. So, instead, decided to experiment with the General tires, and they only cost ~$340 + tax
5. I think I've come to the conclusion that I prefer OEM sizing - figure the engineers knew what they were doing with regard to vehicle dynamics, so why gainsay them?
6. Now, plan is when the front tires wear out, I'll get all 4 MPS4S's OEM size, having conducted my experiment to my satisfaction

Come on! I'm a man with a plan!
if your stock 245 front and 275 rear. Isn't that messing w/the DCS?
Appreciate 0
      08-01-2020, 06:04 PM   #11
cptobvious
Captain
cptobvious's Avatar
United_States
2532
Rep
825
Posts

Drives: M2C HS DCT
Join Date: Jul 2018
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by omasou View Post
if your stock 245 front and 275 rear. Isn't that messing w/the DCS?
Yes, that's a really good point. I'd thought of that, but the reason I went with 275 is according to Tirerack, the tread width of the General 275/35/19 is 9.5" while the tread width on the MPSS 265/35/19 is 9.4"

My understanding is that tread width is ultimately most important with regard to DSC? But, I could be totally talking out of my A** and happy to be corrected!
Appreciate 0
      08-01-2020, 06:14 PM   #12
omasou
Colonel
omasou's Avatar
United_States
2080
Rep
2,999
Posts

Drives: BMWs
Join Date: Apr 2016
Location: US

iTrader: (4)

Garage List
2023 BMW S1000RR  [0.50]
2022 BMW F900XR  [3.00]
2022 BMW X6 40i  [0.50]
2020 BMW M2C  [9.50]
Quote:
Originally Posted by cptobvious View Post
Yes, that's a really good point. I'd thought of that, but the reason I went with 275 is according to Tirerack, the tread width of the General 275/35/19 is 9.5" while the tread width on the MPSS 265/35/19 is 9.4"

My understanding is that tread width is ultimately most important with regard to DSC? But, I could be totally talking out of my A** and happy to be corrected!
So your assumption is 35% of the General 275mm = 35% of the MPSS 265 b/c the tread width are equal? Sounds logical, just not sure if it's accurate? Sure someone else will chime in.
Appreciate 0
      08-01-2020, 06:15 PM   #13
Tag
this is the way
Tag's Avatar
17910
Rep
8,457
Posts

Drives: N-1 starfighter
Join Date: Jan 2007
Location: Chicago

iTrader: (3)

Quote:
Originally Posted by cptobvious View Post
Too funny!

Since you're giving me stick, here was my rationale:

1. Rear tires wore out, but my front tires are still in really good shape
2. Also, wanted to play around with tire size
3. If I experimented with MPS4S's, that would have cost me ~$640 + tax
4. So, instead, decided to experiment with the General tires, and they only cost ~$340 + tax
5. I think I've come to the conclusion that I prefer OEM sizing - figure the engineers knew what they were doing with regard to vehicle dynamics, so why gainsay them?
6. Now, plan is when the front tires wear out, I'll get all 4 MPS4S's OEM size, having conducted my experiment to my satisfaction

Come on! I'm a man with a plan!
You should have still consulted us, we could have confused you more than you already were.
Appreciate 1
cptobvious2531.50
      08-01-2020, 06:29 PM   #14
cptobvious
Captain
cptobvious's Avatar
United_States
2532
Rep
825
Posts

Drives: M2C HS DCT
Join Date: Jul 2018
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by omasou View Post
Quote:
Originally Posted by cptobvious View Post
Yes, that's a really good point. I'd thought of that, but the reason I went with 275 is according to Tirerack, the tread width of the General 275/35/19 is 9.5" while the tread width on the MPSS 265/35/19 is 9.4"

My understanding is that tread width is ultimately most important with regard to DSC? But, I could be totally talking out of my A** and happy to be corrected!
So your assumption is 35% of the General 275mm = 35% of the MPSS 265 b/c the tread width are equal? Sounds logical, just not sure if it's accurate? Sure someone else will chime in.
No, you're right. Damn! Obviously the 275 tire has larger sidewalls.

Well, in any event, once the front MPSS wear out, I'll be getting all MPS4S's in OEM size.
Appreciate 0
      08-01-2020, 06:45 PM   #15
medphysdave
Brigadier General
medphysdave's Avatar
United_States
4526
Rep
4,644
Posts

Drives: M2 CS | 85 of 592
Join Date: Apr 2015
Location: Charlotte, NC

iTrader: (3)

That's about an 11% deviation, and would be regarded as significant. From an experience perspective a 2psi difference is noticeable. It's likely tire dependent to a degree, but 4psi is substantial.
Appreciate 1
cptobvious2531.50
      08-01-2020, 08:02 PM   #16
VisualEcho
Banned
VisualEcho's Avatar
United_States
6626
Rep
4,145
Posts

Drives: '18 M2 6MT
Join Date: Sep 2019
Location: Missouri

iTrader: (1)

Garage List
2018 BMW M2  [10.00]
Quote:
Originally Posted by cptobvious View Post
Yes, that's a really good point. I'd thought of that, but the reason I went with 275 is according to Tirerack, the tread width of the General 275/35/19 is 9.5" while the tread width on the MPSS 265/35/19 is 9.4"

My understanding is that tread width is ultimately most important with regard to DSC? But, I could be totally talking out of my A** and happy to be corrected!
Not sure about DSC, or DCS, or whatever it is, but when it comes to the driving dynamics, as pertains to oversteer and understeer, then yes, the TW is very important, and .1 is negligible.

However, RAKE is super important to some driving systems, so choosing a taller sidewall in just the front or the rear can have a terrible impact on how the car loads each tire, which can confuse all sorts of systems.
Appreciate 1
cptobvious2531.50
      08-01-2020, 08:45 PM   #17
Mavus
Colonel
Mavus's Avatar
2015
Rep
2,659
Posts

Drives: E90 335i, F80 zcp
Join Date: Sep 2011
Location: PA

iTrader: (9)

Quote:
Originally Posted by cptobvious View Post
Quote:
Originally Posted by omasou View Post
Quote:
Originally Posted by cptobvious View Post
Yes, that's a really good point. I'd thought of that, but the reason I went with 275 is according to Tirerack, the tread width of the General 275/35/19 is 9.5" while the tread width on the MPSS 265/35/19 is 9.4"

My understanding is that tread width is ultimately most important with regard to DSC? But, I could be totally talking out of my A** and happy to be corrected!
So your assumption is 35% of the General 275mm = 35% of the MPSS 265 b/c the tread width are equal? Sounds logical, just not sure if it's accurate? Sure someone else will chime in.
No, you're right. Damn! Obviously the 275 tire has larger sidewalls.

Well, in any event, once the front MPSS wear out, I'll be getting all MPS4S's in OEM size.
go 255f 275r since the car is undertired from factory
Appreciate 1
cptobvious2531.50
      08-01-2020, 08:50 PM   #18
KevinM
Brigadier General
KevinM's Avatar
2931
Rep
3,285
Posts

Drives: 2002 M5;2007 M Coupe;2020 M2C
Join Date: Jul 2011
Location: Tucson

iTrader: (0)

Garage List
2020 M2 Competition  [10.00]
2007 E86 M coupe  [8.38]
2002 E39 M5  [9.00]
Quote:
Originally Posted by Tag View Post
Yes, it makes a difference. Just like not having four MPS4S makes a difference.

This makes me wonder why you didn't consult your brethren before purchasing tires? Don't you trust us, impulse buying at the local Walmart, honeymoon with the car over, sleep walking... again, covid brain fog, ate too much cap'n crunch, cptobvious?
He didn't want to deal with all of us saying, "Dude, just get MPS4S..."
__________________
2020 F87 M2C Hockenheim Silver/MT
2002 E39 M5 Sterling Gray/Caramel
2007 E86 Z4M Coupe Silver Gray/Black
2021 Kia Telluride (hauler)
Appreciate 2
cptobvious2531.50
Tag17910.00
      08-01-2020, 08:57 PM   #19
///AVM
Banned
United_States
2528
Rep
1,908
Posts

Drives: G80 M3C
Join Date: Aug 2019
Location: U.S.A.

iTrader: (0)

Quote:
Originally Posted by cptobvious View Post
G. . . Immediately felt like the car was unsettled and twitchy when pushed . . .
So, thinking of Cpt's statement and Tag's open invitation toward forum member feedback . . .

I know one thing a lot of people like about the M2C is it's loose rear end, or what we like to call 'playful.' I personally wish I could get a little more grip than slip. In this regard . . .

1. Has anyone switched from PSS to PS4S and feel the dry pavement grip was noticeably improved? Overall ride quality noticeably different, better or worse? I have experience with both tires, but not on the same vehicle so my bias toward the PS4S is more opinion than validated.

2. I have never looked up the recommended PSS psi for the M2C. I am assuming my psi are set at recommended. Has anyone dropped the psi 2 or 3 below recommended on stock (PSS) tires? My suspicion is this might give a little more road grip I am after, as well as less firm ride quality.

3. I assume the tire pressure 'alert' does not go off until the reading is +/-4 from recommended? Can anyone verify the 'alert' range?

Thank you

///AVM

Last edited by ///AVM; 08-02-2020 at 02:33 PM..
Appreciate 0
      08-01-2020, 10:05 PM   #20
VisualEcho
Banned
VisualEcho's Avatar
United_States
6626
Rep
4,145
Posts

Drives: '18 M2 6MT
Join Date: Sep 2019
Location: Missouri

iTrader: (1)

Garage List
2018 BMW M2  [10.00]
Quote:
Originally Posted by Smooth 330i View Post
Quote:
Originally Posted by cptobvious View Post
Quote:
Originally Posted by omasou View Post
Quote:
Originally Posted by cptobvious View Post
Yes, that's a really good point. I'd thought of that, but the reason I went with 275 is according to Tirerack, the tread width of the General 275/35/19 is 9.5" while the tread width on the MPSS 265/35/19 is 9.4"

My understanding is that tread width is ultimately most important with regard to DSC? But, I could be totally talking out of my A** and happy to be corrected!
So your assumption is 35% of the General 275mm = 35% of the MPSS 265 b/c the tread width are equal? Sounds logical, just not sure if it's accurate? Sure someone else will chime in.
No, you're right. Damn! Obviously the 275 tire has larger sidewalls.

Well, in any event, once the front MPSS wear out, I'll be getting all MPS4S's in OEM size.
go 255f 275r since the car is undertired from factory
Depends on your driving style and the tires you choose. Some, like myself, like it playful and loose, I'm not competing on my commute. And with regards to tires, the MPSS runs wide, so if you're not careful you can get 255/275 that are no wider at all, and possibly skinnier.
Appreciate 0
      08-01-2020, 10:21 PM   #21
bri1042
Brigadier General
bri1042's Avatar
5744
Rep
3,244
Posts

Drives: 2021 IOMG M3 6MT
Join Date: Mar 2013
Location: Portland, OR

iTrader: (0)

AVM - Folk have switched to the 4S's, at various tire sizes. I basically agree that the playfulness of the original tires is fun, and it appeals to reviewers of high skill like Chris Harris. However, I know I'm not at his skill level, I daily the car in rain and shine, and I was interested in seeing how the car would work out with more grip, even if it sacrificed a little playfulness. Cup 2's were right out because of the sheer number of wet days I have to drive this car on.

I went to Apex EC-7 wheels running PS4S 265/30's and 295/30's. It's made a the car a bit more serious, but I'm connecting with it more, skill-wise and just with what I want out of the car. It's more predictable and I'm very much enjoying it's behavior off the line with the increased grip.

The PS4S's are quieter and they transmit a lot less vibration into the cabin. I don't know how much more "grippy" they'd be at OEM sizes...at least a bit, I'd think.
Appreciate 0
      08-01-2020, 10:36 PM   #22
xxyion
Captain
xxyion's Avatar
756
Rep
785
Posts

Drives: 2024 M4 Competition xDrive
Join Date: Dec 2019
Location: Fremont CA

iTrader: (0)

it seems like most people have answered the question but take this into consideration.

When your tires heat up it increases tire PSI, so carefully think about when you measured your tire pressure. Did you do it after driving it for a bit? If you did, and then adjusted it then, it means you like your tire pressure at around 32ish PSI give or take cold.

tire PSI gets pretty nuts in the autocross group. People get obsessed down to the psi when they do runs. and even measure after every run.
Appreciate 1
cptobvious2531.50
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:30 AM.




m2
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST