Upsizing tire side walls

Dallasguy1985 · 05-31-2022, 01:05 PM

So I'm in the process of buying summer tires to replace the factory RFTs came across a G30 with taller side walls 245/40/20 and 275/35/20 I couldn't ask questions will this cause any issues or problem down the road I remember having drivetrain warnings in my older 435. Appreciate the inputs. Thanks

Joe-BMW33 · 05-31-2022, 01:14 PM

I am not the de facto expert on this, but from all I have read, you will have issues. The diameter of the wheel and tire together needs to be the same as spec. If you want a larger sidewall, you will have to drop down to 19's.

What are you after here? Reducing the gap?

Dallasguy1985 · 05-31-2022, 01:29 PM

Quote:

Originally Posted by Joe-BMW33

I am not the de facto expert on this, but from all I have read, you will have issues. The diameter of the wheel and tire together needs to be the same as spec. If you want a larger sidewall, you will have to drop down to 19's.

What are you after here? Reducing the gap?

Don't care about the gap just want more rubber on the wheels roads are bad in Texas.

Joe-BMW33 · 05-31-2022, 01:37 PM

Quote:

Originally Posted by Dallasguy1985

Don't care about the gap just want more rubber on the wheels roads are bad in Texas.

Got it, but moving down to 19's is better for that, it kind of defeats the purpose of low profile 20's which is really all about looks. IMO, I think the rubber on the picture you posted look horribly our of place. Almost Cross-Over ish.

AP · 05-31-2022, 01:44 PM

Also note if the diameter changes your speed will under or over read

I'm guessing the list of possible tyre sizes I drive may not potentially list what you are chasing to ( great if it does)
Just worth beating mind

cna90 · 05-31-2022, 01:46 PM

I've seen people doing it. They're 7 series sizes.
Not sure there is a way you can code the transfer case or not. I always wondered under tire selection, "other tires" means the transfer case detect them automatically or not.

I would switch to 19" rims over 20" and keep them as OEM diameter to be safe. In case you get flat and have to put the spare on they will be miss matched and that for sure will brake the transfer case.
My winters are 19" and they're night and day in comparison.
If I get another flat on 20s I'm gonna go all in 19" as well.

m7mad · 06-05-2022, 07:10 AM

I have been running these sizes for over 6 months now, no problems whatsoever (mine is 540i RWD), They certainly look good on a wider wheels. Regarding speedometer reading now its on par with GPS speed stock setup up was off by 3 kilometers.

here are two photos same size but different wheels.

Mach550 · 06-05-2022, 03:50 PM

I went +5 front and back and probably have almost 10,000 miles on the tires with no issues. Huge benefit is the extra protection and the accurate (compared to GPS and the annoying speed limit radar signs) speedometer.

HerkHealer · 06-05-2022, 04:05 PM

Quote:

Originally Posted by Mach550

I went +5 front and back and probably have almost 10,000 miles on the tires with no issues. Huge benefit is the extra protection and the accurate (compared to GPS and the annoying speed limit radar signs) speedometer.

What tire did you buy ? I really like the PS4S tire and how the sidewall "bulges" out making the tire look wider than it is. Also helps protect curb rash to the wheel.

Mach550 · 06-05-2022, 04:16 PM

Quote:

Originally Posted by HerkHealer

What tire did you buy ? I really like the PS4S tire and how the sidewall "bulges" out making the tire look wider than it is. Also helps protect curb rash to the wheel.

PS4S's, I tried continentals in the past and didn't like them.

HerkHealer · 06-05-2022, 04:19 PM

Quote:

Originally Posted by Mach550

PS4S's, I tried continentals in the past and didn't like them.

Awesome. Did you notice any cornering difference by going up 5 ? Probably not. I live in NH and the roads are not great here. I've already bent one wheel.

Are you on the 668's ? Can you send a pic ?

Mach550 · 06-05-2022, 04:23 PM

I'm not totally sure but I think these are them. No issues and I spend most of my time sport+ individual

Joe-BMW33 · 06-05-2022, 05:40 PM

Quote:

Originally Posted by Mach550

I'm not totally sure but I think these are them. No issues and I spend most of my time sport+ individual

Beautiful. Those are 668s.

Joe-BMW33 · 06-05-2022, 05:43 PM

Quote:

Originally Posted by m7mad

I have been running these sizes for over 6 months now, no problems whatsoever (mine is 540i RWD), They certainly look good on a wider wheels. Regarding speedometer reading now its on par with GPS speed stock setup up was off by 3 kilometers.

here are two photos same size but different wheels.

[IMG]https://serving.photos.photobox.com/...c9d83da6c5.jpg[/IMG]

[IMG]https://serving.photos.photobox.com/...e131ade56b.jpg[/IMG]

Maybe it's me and knowing those tires are not stock, but there's just something "thick" about them. Especially the second pic.

HerkHealer · 06-05-2022, 05:49 PM

Quote:

Originally Posted by Mach550

I'm not totally sure but I think these are them. No issues and I spend most of my time sport+ individual

WOW!

That is really a impressive upgrade vs stock wheel/tire/opening upgrade.
I just put on the stock sized PS4S tires and cant say nothing but excellent about them, but the extra sidewall really fills the fender in and most importantly will help to prevent wheel damage.

NGT2 · 06-05-2022, 11:43 PM

Quote:

Originally Posted by m7mad

I have been running these sizes for over 6 months now, no problems whatsoever (mine is 540i RWD), They certainly look good on a wider wheels. Regarding speedometer reading now its on par with GPS speed stock setup up was off by 3 kilometers.

here are two photos same size but different wheels.

I like it. What size wheel and tires are those?

SonD · 06-06-2022, 09:18 AM

Quote:

Originally Posted by Mach550

I'm not totally sure but I think these are them. No issues and I spend most of my time sport+ individual

May I ask what colour that is please?
I am about to order a set of those 668 later this month when my 545E finally goes into production as a set of summer wheels.
I am rather more stuck for tyre choice, as runflats are really needed on it due to very limited space even for a skinny spare.
While the PS 4 S looks like the current summer tyre of choice here, it's a no go in RunFlat :-(

Mach550 · 06-06-2022, 11:10 AM

Quote:

Originally Posted by SonD

May I ask what colour that is please?
I am about to order a set of those 668 later this month when my 545E finally goes into production as a set of summer wheels.
I am rather more stuck for tyre choice, as runflats are really needed on it due to very limited space even for a skinny spare.
While the PS 4 S looks like the current summer tyre of choice here, it's a no go in RunFlat :-(

Mediterranean Blue, I have all the details in my signature.

05-31-2022, 01:05 PM	#1
Dallasguy1985 Private 75 Rep 87 Posts Drives: 535 Join Date: Feb 2015 Location: Dallas iTrader: (0)	So I'm in the process of buying summer tires to replace the factory RFTs came across a G30 with taller side walls 245/40/20 and 275/35/20 I couldn't ask questions will this cause any issues or problem down the road I remember having drivetrain warnings in my older 435. Appreciate the inputs. Thanks Attached Images
	Appreciate 0 Tweet Quote

05-31-2022, 01:14 PM	#2
Joe-BMW33 Major General 7476 Rep 6,848 Posts Drives: '18 M550i\|'21 X5\|'03 540i Join Date: Apr 2021 Location: Boston iTrader: (1) Garage List 2013 VW Tiguan [0.00] 2015 Infiniti QX60 [0.00] 2021 BMW X5 [0.00] 2003 BMW 540i [0.00] 2018 BMW M550 [10.00]	I am not the de facto expert on this, but from all I have read, you will have issues. The diameter of the wheel and tire together needs to be the same as spec. If you want a larger sidewall, you will have to drop down to 19's. What are you after here? Reducing the gap? __________________ 2018 M550ix\|Carbon Black\|Dinan Modifications\|2003 540i\|Jet Black\|M-Sport\|2021 X5 Mineral White Prior BMW's: 1987 325e\|1993 740i\|1998 740il\|2001 530i\|2002 745li\|2007 750li\|2006 750li\|2001 530i\|2012 535xi\|
	Appreciate 0 Quote

05-31-2022, 01:44 PM	#5
AP Major General 2852 Rep 5,146 Posts Drives: G30 M550 Join Date: Apr 2011 Location: UK iTrader: (0)	Also note if the diameter changes your speed will under or over read I'm guessing the list of possible tyre sizes I drive may not potentially list what you are chasing to ( great if it does) Just worth beating mind
	Appreciate 0 Quote

05-31-2022, 01:46 PM	#6
cna90 First Lieutenant 178 Rep 307 Posts Drives: BMW 540ix with MPPSK Join Date: Aug 2021 Location: Toronto iTrader: (0)	I've seen people doing it. They're 7 series sizes. Not sure there is a way you can code the transfer case or not. I always wondered under tire selection, "other tires" means the transfer case detect them automatically or not. I would switch to 19" rims over 20" and keep them as OEM diameter to be safe. In case you get flat and have to put the spare on they will be miss matched and that for sure will brake the transfer case. My winters are 19" and they're night and day in comparison. If I get another flat on 20s I'm gonna go all in 19" as well.
	Appreciate 1 Joe-BMW337475.50 Quote

06-05-2022, 07:10 AM	#7
m7mad Private First Class 101 Rep 137 Posts Drives: G30 540i Join Date: Jul 2016 Location: KSA iTrader: (0)	I have been running these sizes for over 6 months now, no problems whatsoever (mine is 540i RWD), They certainly look good on a wider wheels. Regarding speedometer reading now its on par with GPS speed stock setup up was off by 3 kilometers. here are two photos same size but different wheels. __________________ 2018 G30 540i 2011 M3 E92
	Appreciate 0 Quote

06-05-2022, 03:50 PM	#8
Mach550 Captain 473 Rep 894 Posts Drives: 2019 M550i Join Date: Aug 2018 Location: Tampa Bay iTrader: (0) Garage List 2019 BMW M550i [8.00]	I went +5 front and back and probably have almost 10,000 miles on the tires with no issues. Huge benefit is the extra protection and the accurate (compared to GPS and the annoying speed limit radar signs) speedometer. __________________ M550i Build
	Appreciate 1 HerkHealer1744.00 Quote

06-05-2022, 04:23 PM	#12
Mach550 Captain 473 Rep 894 Posts Drives: 2019 M550i Join Date: Aug 2018 Location: Tampa Bay iTrader: (0) Garage List 2019 BMW M550i [8.00]	I'm not totally sure but I think these are them. No issues and I spend most of my time sport+ individual __________________ M550i Build
	Appreciate 0 Quote