Advice on tire size

Rafale · 08-19-2010, 11:28 PM

Been thinking about going wider or larger when I will be switching out my RFTs.
Since I have 18" my front wheels ar 8" wide and the rear are 8.5".

I am limited to go: 235/40/18 front and 255/40/18 rear.
Any idea if it will fit? The width should work fine, it is the diameter which is risky:
The front tire diameter will go from 25.1" to 25.4"
The rear from 25" (25.2" according to the tirerack for PS2) to 26"

I don't know if the rear wheel well can take half an inch increase in radius...

What size are the 19" running?

Memphis1 · 08-20-2010, 12:07 AM

For 18" rims (18x8 and 18x8.5) you can go with 225/40 and 255/35

For 19" rims (19x8.5 and 19x9) you can go with 235/35 and 265/30, you can try to get away with 245/30 and 275/25.

The max is 245/30/20 F 285/25/20 R

Rafale · 08-20-2010, 12:31 AM

Thanks.
The 20" you gave give a diameter of 25.8" and 25.6" F/R so I guess that would be the max diameter I should go with. It would leave me at 18" with
F 235/40/18 (25.4")
R 245/40/18 (25.7")

Banton · 08-20-2010, 12:42 AM

One thing to be concerned with on the overall circumference is the revolutions per mile. The bigger you go, the more out of sync your speedo will be. Best to match tire height, regardless of footprint, with your current overall height.

Rafale · 08-20-2010, 12:44 AM

As a matter of fact I am trying to compensate for the notorious speedo error on the bimmers... That's why I am looking to go taller.

Memphis1 · 08-20-2010, 05:03 AM

The difference is irrelevant, 1mph at most

http://e89.zpost.com/forums/showthre...ghlight=Speedo

Rafale · 08-20-2010, 10:32 AM

Actually it is almost 3%. at 80mph it is over 2.2 mph...

fisherman · 08-20-2010, 11:10 AM

Rafale- I also have a 30i with the 18 " wheels. What kind of mileage did you get on your factory RFT's ? I get the feeling these tires are not known for lasting 30,000 miles !

Steve

Rafale · 08-20-2010, 11:55 AM

These RFT will last 10000-15000 if you drive them carefully. I am swapping them because I am annoyed by the noise and the ride.

ttuner · 08-20-2010, 12:02 PM

http://www.1010tires.com/tiresizecalculator.asp

fisherman · 08-20-2010, 01:51 PM

Quote:

Originally Posted by Rafale

These RFT will last 10000-15000 if you drive them carefully. I am swapping them because I am annoyed by the noise and the ride.

I only have 750 miles so far, so I've got a ways to go ! 10,000 at the low end is not very good....
I haven't noticed any noise or ride issues with the tires so far .....I actually love the ride ( of corse, my other car is a truck, so I may not be the best judge...

Rafale · 08-20-2010, 02:03 PM

Quote:

Originally Posted by fisherman

I only have 750 miles so far, so I've got a ways to go ! 10,000 at the low end is not very good....
I haven't noticed any noise or ride issues with the tires so far .....I actually love the ride ( of corse, my other car is a truck, so I may not be the best judge...

Well. I have an e46 to compare to with the exact same size of tires... So I can tell you these tires are really noisy and drive really harsh.

Silver-Bolt · 08-20-2010, 02:16 PM

Quote:

Originally Posted by fisherman

I only have 750 miles so far, so I've got a ways to go ! 10,000 at the low end is not very good....
I haven't noticed any noise or ride issues with the tires so far .....I actually love the ride ( of corse, my other car is a truck, so I may not be the best judge...

They will get considerably louder as they wear.

cwliew · 08-20-2010, 04:07 PM

Just wondering - are all 19 inch options wider as well
I have 326m wheels. Are they wider than 325ms or other 18 inch wheels?

Rafale · 08-20-2010, 05:00 PM

the 18 are 8x18 front, 8.5x18 rear
the 19 are 8.5x19 front and 9x19 rear...

Memphis posted that. This means that you have the opportunity to install 275 in the rear for 19" and 255 in the front.

Memphis1 · 08-20-2010, 05:03 PM

sry, just a correction, the 19" sizes are aftermarket, not bmw's 326M's, those are 19x8 and 19x9

also i quoted 245 as the max front size

Rafale · 08-20-2010, 05:17 PM

Quote:

Originally Posted by Memphis1

sry, just a correction, the 19" sizes are aftermarket, not bmw's 326M's, those are 19x8 and 19x9

also i quoted 245 as the max front size

if they are 19x8 then yeah, 245 is the max you can get.

Dr Stig 2 · 08-20-2010, 05:53 PM

Over here, it is more an insurance issue.
Most policies have a clause that states that you are not covered if your wheel & tyre sizes differs from the OEM sizing.
Just another way they try to get out of paying up...

Memphis1 · 08-20-2010, 06:12 PM

Quote:

Originally Posted by Rafale

if they are 19x8 then yeah, 245 is the max you can get.

no, what i mean is that regardless of the rim, 245 is max because 255 will rub when you turn your steering wheel and against the fender when you go over bumps...

Furkanyahsi · 05-25-2014, 08:42 AM

Size: 9.5x19
Offset: 33
P.C.D.: 5x120
Centerbore: 72.6

Hello guys im going to buy vmr710, i want to know is it fit or not ?

9.5x19 http://www.vmrwheels.eu/eu/VMR-Wheel...0-72-6-GM.html

8.5x19 http://www.vmrwheels.eu/eu/VMR-Wheel...0-72-6-GM.html

08-19-2010, 11:28 PM	#1
Rafale Zed Quatre 24 Rep 410 Posts Drives: '11 Z4 35is & '11 535xi GT Join Date: Jun 2010 Location: Portland, OR. USA iTrader: (1) Garage List 2011 535i GT xDrive [0.00] 2011 Z4 35is [7.00]	Advice on tire size Been thinking about going wider or larger when I will be switching out my RFTs. Since I have 18" my front wheels ar 8" wide and the rear are 8.5". I am limited to go: 235/40/18 front and 255/40/18 rear. Any idea if it will fit? The width should work fine, it is the diameter which is risky: The front tire diameter will go from 25.1" to 25.4" The rear from 25" (25.2" according to the tirerack for PS2) to 26" I don't know if the rear wheel well can take half an inch increase in radius... What size are the 19" running?
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08-20-2010, 12:07 AM	#2
Memphis1 Lieutenant Colonel 89 Rep 1,838 Posts Drives: Z4 SDrive 35i Join Date: Oct 2009 Location: CT iTrader: (0)	For 18" rims (18x8 and 18x8.5) you can go with 225/40 and 255/35 For 19" rims (19x8.5 and 19x9) you can go with 235/35 and 265/30, you can try to get away with 245/30 and 275/25. The max is 245/30/20 F 285/25/20 R __________________
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08-20-2010, 12:31 AM	#3
Rafale Zed Quatre 24 Rep 410 Posts Drives: '11 Z4 35is & '11 535xi GT Join Date: Jun 2010 Location: Portland, OR. USA iTrader: (1) Garage List 2011 535i GT xDrive [0.00] 2011 Z4 35is [7.00]	Thanks. The 20" you gave give a diameter of 25.8" and 25.6" F/R so I guess that would be the max diameter I should go with. It would leave me at 18" with F 235/40/18 (25.4") R 245/40/18 (25.7")
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08-20-2010, 12:42 AM	#4
Banton Enlisted Member 0 Rep 44 Posts Drives: ordered: '11 35is loaded Join Date: Jul 2010 Location: Bainbridge Island, WA & Brentwood, CA iTrader: (0)	One thing to be concerned with on the overall circumference is the revolutions per mile. The bigger you go, the more out of sync your speedo will be. Best to match tire height, regardless of footprint, with your current overall height.
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08-20-2010, 12:44 AM	#5
Rafale Zed Quatre 24 Rep 410 Posts Drives: '11 Z4 35is & '11 535xi GT Join Date: Jun 2010 Location: Portland, OR. USA iTrader: (1) Garage List 2011 535i GT xDrive [0.00] 2011 Z4 35is [7.00]	As a matter of fact I am trying to compensate for the notorious speedo error on the bimmers... That's why I am looking to go taller.
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08-20-2010, 05:03 AM	#6
Memphis1 Lieutenant Colonel 89 Rep 1,838 Posts Drives: Z4 SDrive 35i Join Date: Oct 2009 Location: CT iTrader: (0)	The difference is irrelevant, 1mph at most http://e89.zpost.com/forums/showthre...ghlight=Speedo __________________
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08-20-2010, 10:32 AM	#7
Rafale Zed Quatre 24 Rep 410 Posts Drives: '11 Z4 35is & '11 535xi GT Join Date: Jun 2010 Location: Portland, OR. USA iTrader: (1) Garage List 2011 535i GT xDrive [0.00] 2011 Z4 35is [7.00]	Actually it is almost 3%. at 80mph it is over 2.2 mph...
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08-20-2010, 11:10 AM	#8
fisherman Private 2 Rep 92 Posts Drives: 2011 sDrive 30i Join Date: Jul 2010 Location: RI iTrader: (0)	tire mileage Rafale- I also have a 30i with the 18 " wheels. What kind of mileage did you get on your factory RFT's ? I get the feeling these tires are not known for lasting 30,000 miles ! Steve
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08-20-2010, 11:55 AM	#9
Rafale Zed Quatre 24 Rep 410 Posts Drives: '11 Z4 35is & '11 535xi GT Join Date: Jun 2010 Location: Portland, OR. USA iTrader: (1) Garage List 2011 535i GT xDrive [0.00] 2011 Z4 35is [7.00]	These RFT will last 10000-15000 if you drive them carefully. I am swapping them because I am annoyed by the noise and the ride.
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08-20-2010, 12:02 PM	#10
ttuner First Lieutenant 67 Rep 378 Posts Drives: z4 Join Date: Jul 2010 Location: phx iTrader: (0)	http://www.1010tires.com/tiresizecalculator.asp
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08-20-2010, 04:07 PM	#14
cwliew Private 9 Rep 56 Posts Drives: Sdrive30i, M sports pack Join Date: May 2010 Location: Adelaide, Australia iTrader: (0)	Just wondering - are all 19 inch options wider as well I have 326m wheels. Are they wider than 325ms or other 18 inch wheels?
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08-20-2010, 05:00 PM	#15
Rafale Zed Quatre 24 Rep 410 Posts Drives: '11 Z4 35is & '11 535xi GT Join Date: Jun 2010 Location: Portland, OR. USA iTrader: (1) Garage List 2011 535i GT xDrive [0.00] 2011 Z4 35is [7.00]	the 18 are 8x18 front, 8.5x18 rear the 19 are 8.5x19 front and 9x19 rear... Memphis posted that. This means that you have the opportunity to install 275 in the rear for 19" and 255 in the front.
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08-20-2010, 05:03 PM	#16
Memphis1 Lieutenant Colonel 89 Rep 1,838 Posts Drives: Z4 SDrive 35i Join Date: Oct 2009 Location: CT iTrader: (0)	sry, just a correction, the 19" sizes are aftermarket, not bmw's 326M's, those are 19x8 and 19x9 also i quoted 245 as the max front size __________________
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08-20-2010, 05:53 PM	#18
Dr Stig 2 Criminally Insane 53 Rep 1,464 Posts Drives: Like a Demon! Join Date: Jun 2010 Location: Brisbane, Australia iTrader: (0) Garage List 2010 BMW Z4 35is [10.00] 2013 BMW X5 30d [0.00]	Over here, it is more an insurance issue. Most policies have a clause that states that you are not covered if your wheel & tyre sizes differs from the OEM sizing. Just another way they try to get out of paying up... __________________ Dr Stig 2010 Z4 35is 2011 X3 30d M Sport Australia
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05-25-2014, 08:42 AM	#20
Furkanyahsi Enlisted Member 3 Rep 36 Posts Drives: Z4 35i Join Date: Nov 2013 Location: Istanbul iTrader: (0)	Size: 9.5x19 Offset: 33 P.C.D.: 5x120 Centerbore: 72.6 Hello guys im going to buy vmr710, i want to know is it fit or not ? 9.5x19 http://www.vmrwheels.eu/eu/VMR-Wheel...0-72-6-GM.html 8.5x19 http://www.vmrwheels.eu/eu/VMR-Wheel...0-72-6-GM.html
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