What tire size for 21" Wheels

pochesq · 03-21-2013, 12:15 PM

I'm debating whether to go 305/25/21 or 295/25/21 in the rear. My concern is a combination of asthetics, ride quality, and performance. I know some members on this board are running 295s and some 305s. With an H&R drop, what are your thoughts on the size of the tires? Thanks in advance.

Poleposition · 03-21-2013, 12:19 PM

Depends heavily on your offsets and type of tire you plan to run.

pochesq · 03-21-2013, 12:30 PM

Quote:

Originally Posted by Poleposition

Depends heavily on your offsets and type of tire you plan to run.

Still haven't decided on the wheel, but maybe HRE or DPE (I don't know the offsets). The tires would be either Michelin, Pirelli or Falken. Thanks.

mwlmd · 03-21-2013, 12:37 PM

Michelin has the 305/25/21 PSS listed as a smaller total diameter than than the 295/25/21. Is that possible?

johntomferg · 03-21-2013, 01:31 PM

Quote:

Originally Posted by mwlmd

Michelin has the 305/25/21 PSS listed as a smaller total diameter than than the 295/25/21. Is that possible?

You need to be careful to not under rate the weight capacity of the tires. I think the ones you are looking at do not have the minimum capacity of the stock tire sizes:

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Link to Tire Rack: http://www.tirerack.com/tires/tires....5&autoModClar=

This could also play a role in determining tire diameter based on deflection.

pochesq · 03-21-2013, 02:09 PM

I know many people who have 21" wheels are driving 265s in front and 295 or 305s in the rear. Would there be an issue if I have a set-up of 255/295? Thanks again. Some posts were way too technical for me. I'm a lawyer and not an engineer. hahaha Thanks and keep them coming.

Charlie Brown · 03-26-2013, 05:58 AM

Quote:

Originally Posted by mwlmd

Michelin has the 305/25/21 PSS listed as a smaller total diameter than than the 295/25/21. Is that possible?

Mathematically speaking, no it's not possible. 295/25-21= 26.8" (680.9mm) diameter. 305/25-21= 27" (685.9mm) diameter. I believe the chart has a typo or misprint.

tony.m6 · 10-26-2014, 12:34 PM

I can't decide on wheels to buy 20" or 21" ???
I'm scared if I go with 21" I might lose performance.... What do you guys think ????

If you have 21" wheels please leave you feedback on your experiences

double trouble · 10-26-2014, 05:40 PM

Quote:

Originally Posted by pochesq

I know many people who have 21" wheels are driving 265s in front and 295 or 305s in the rear. Would there be an issue if I have a set-up of 255/295? Thanks again. Some posts were way too technical for me. I'm a lawyer and not an engineer. hahaha Thanks and keep them coming.

Is this a toyo T1R you're referencing? Be careful because they're not XL load rated, which is a factory spec.

I have been trying for months to get a 305/25/21 setup, but Michelin discontinued them, and Tire Rack is reporting that Pirelli is on back order until Feb 2015.

I'm currently looking for other options too, but I just can't find any.

Ben

Igor_M5 · 05-02-2015, 03:02 PM

Anyone ever ran or seen 305/30/21 or 295/30/21 on a 11.5"? Any fitment issues?

mrainv23 · 05-16-2015, 09:31 AM

The load rating is significantly under when you run 255s and 295s on a 21" wheel. Curb weight is fine but when driving aggressively the weight shifts and can cause a blow out. I recently ran into this issue on my M6 and was fortunate to locate a set of michelin pss 265/30zr 21 and 305/25zr 21 setup. I confirmed this with BMW, tire rack, and discount tire. They would not mount the pirellis on my car due to liability.

vividracing · 05-22-2015, 07:44 PM

We ran the 255/30 front and 295/25 rear in a Yokohama Advan Sport tire, and the fitment was pretty dead on, with our particular offset the 305 wouldve definitely had issues.

The main problem right now in these sizes is availability, Michelin has been on a national backorder for a while now.

MCarsFan · 05-23-2015, 10:45 AM

Quote:

Originally Posted by mrainv23

The load rating is significantly under when you run 255s and 295s on a 21" wheel. Curb weight is fine but when driving aggressively the weight shifts and can cause a blow out. I recently ran into this issue on my M6 and was fortunate to locate a set of michelin pss 265/30zr 21 and 305/25zr 21 setup. I confirmed this with BMW, tire rack, and discount tire. They would not mount the pirellis on my car due to liability.

I'm running 305s on stock 343M wheels.. Hope this is okay because the traction has been amazing! If not, I'll just switch back.

M6-Coupe · 05-23-2015, 12:33 PM

Quote:

Originally Posted by MCarsFan

I'm running 305s on stock 343M wheels.. Hope this is okay because the traction has been amazing! If not, I'll just switch back.

What he is referring to is load rating. I think yours must be 99 or 101 right?
If that's the case then you should be fine. The only concern about your setup is the 305 mm tire on 10" rims that we already discussed, but I recall you mentioned that you emailed them and they gave you green light...

MCarsFan · 05-23-2015, 07:27 PM

Quote:

Originally Posted by M6-Coupe

What he is referring to is load rating. I think yours must be 99 or 101 right?
If that's the case then you should be fine. The only concern about your setup is the 305 mm tire on 10" rims that we already discussed, but I recall you mentioned that you emailed them and they gave you green light...

Thanks for clarifying for me..

lsturbointeg · 05-30-2015, 08:24 AM

Quote:

Originally Posted by vividracing

the wheel just compliments the overall aesthetics of the rotors and calipers!

Mr_M5Guy · 12-23-2015, 02:01 PM

Could you run 275/30/21 up front. 265's are really hard to find

Mr_M5Guy · 12-29-2015, 09:01 PM

Bump.

I purchased some Morr 10.2 21" wheels. 9.5f/11r.

My car has an ecu tune, dps, and intake, so I'm looking for the best combination to gain traction. Could I run 275/315 setup?

03-21-2013, 12:15 PM	#1
pochesq Lieutenant 48 Rep 434 Posts Drives: 2013 M5 Join Date: Feb 2013 Location: Southern California iTrader: (0)	What tire size for 21" Wheels I'm debating whether to go 305/25/21 or 295/25/21 in the rear. My concern is a combination of asthetics, ride quality, and performance. I know some members on this board are running 295s and some 305s. With an H&R drop, what are your thoughts on the size of the tires? Thanks in advance.
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03-21-2013, 12:19 PM	#2
Poleposition ~~~~~~~~~~~~~ 512 Rep 1,437 Posts Drives: very well Join Date: Sep 2008 Location: NY iTrader: (2)	Depends heavily on your offsets and type of tire you plan to run. __________________ 2022 Individual M5 Comp Venetian Violet 2021 X6M Comp 2024 i4 M50 on order IG @purpleM5Comp_NY
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03-21-2013, 12:37 PM	#4
mwlmd Lieutenant Colonel 187 Rep 1,548 Posts Drives: Porsche 991 TTS Join Date: May 2009 Location: Portland, OR iTrader: (0)	Michelin has the 305/25/21 PSS listed as a smaller total diameter than than the 295/25/21. Is that possible? __________________ CURRENT: His: Porsche 991 Turbo S Carrera white/Black Hers: BMW X3MC BSM/Black
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03-21-2013, 02:09 PM	#6
pochesq Lieutenant 48 Rep 434 Posts Drives: 2013 M5 Join Date: Feb 2013 Location: Southern California iTrader: (0)	I know many people who have 21" wheels are driving 265s in front and 295 or 305s in the rear. Would there be an issue if I have a set-up of 255/295? Thanks again. Some posts were way too technical for me. I'm a lawyer and not an engineer. hahaha Thanks and keep them coming.
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10-26-2014, 12:34 PM	#8
tony.m6 Captain 131 Rep 687 Posts Drives: M6, CTS-V, F10 M5, TURBO-S Join Date: Dec 2009 Location: Florida-Miami iTrader: (1)	I can't decide on wheels to buy 20" or 21" ??? I'm scared if I go with 21" I might lose performance.... What do you guys think ???? If you have 21" wheels please leave you feedback on your experiences
	Appreciate 0 Quote

05-02-2015, 03:02 PM	#10
Igor_M5 2134 Rep 1,834 Posts Drives: Many, BMW. Join Date: Aug 2007 Location: New York City iTrader: (10) Garage List 2007;2013 E91 335is [10.00]	Anyone ever ran or seen 305/30/21 or 295/30/21 on a 11.5"? Any fitment issues?
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05-16-2015, 09:31 AM	#11
mrainv23 mrainv23 30 Rep 224 Posts Drives: 2014 BMW M6 Gran Coupe F06 Join Date: Jan 2012 Location: Indianapolis iTrader: (0)	The load rating is significantly under when you run 255s and 295s on a 21" wheel. Curb weight is fine but when driving aggressively the weight shifts and can cause a blow out. I recently ran into this issue on my M6 and was fortunate to locate a set of michelin pss 265/30zr 21 and 305/25zr 21 setup. I confirmed this with BMW, tire rack, and discount tire. They would not mount the pirellis on my car due to liability. __________________ 2014 BMW M6 Gran Coupe F06/M Performance Black Grille/20% Tint/ Exec Package/ Driver Assist Plus/ Black on Black Sold-BMW 550i F10/Dinan S3/ Eisenmann Race Exhaust/ Vossen CV3s
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05-22-2015, 07:44 PM	#12
vividracing 685 Rep 6,854 Posts Drives: E90 M3, F30 335i, F80 M3 Join Date: Aug 2006 Location: Arizona iTrader: (14)	We ran the 255/30 front and 295/25 rear in a Yokohama Advan Sport tire, and the fitment was pretty dead on, with our particular offset the 305 wouldve definitely had issues. The main problem right now in these sizes is availability, Michelin has been on a national backorder for a while now. __________________ Travis Williams Shop ALL BMW G80 \| G82 Parts Here! 480.966.3040 ext 318 Travisw@vividracing.com PM, Email, or Call Directly for aggressive BMW Member Pricing
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12-23-2015, 02:01 PM	#17
Mr_M5Guy First Lieutenant 58 Rep 327 Posts Drives: e60 M5 Join Date: Apr 2014 Location: Globe Trecker iTrader: (0)	Could you run 275/30/21 up front. 265's are really hard to find
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12-29-2015, 09:01 PM	#18
Mr_M5Guy First Lieutenant 58 Rep 327 Posts Drives: e60 M5 Join Date: Apr 2014 Location: Globe Trecker iTrader: (0)	Bump. I purchased some Morr 10.2 21" wheels. 9.5f/11r. My car has an ecu tune, dps, and intake, so I'm looking for the best combination to gain traction. Could I run 275/315 setup?
	Appreciate 0 Quote