Tire dimensions Noob Question

Prowller · 09-16-2021, 10:30 AM

Hey guys,

I recently bought a BMW 2017 Series 3 LCI and wanted to buy a pair of run flat tires for the cold season to use with my current r18 rims however, I'm noticing a difference between what the car's certificate has written on it (205/60 ) and the dimensions I have on the current tires, front 225/45 R18 , back 255/40 R18.

Now, I'm a total noob and not sure what to get in terms of dimensions because i have the dimensions on paper, but in real life I got something else (just bought the car 2 months ago) so given that it's also Xdrive, is it a requirement for the tire to be larger on the back or?

Any help or article that can explain it would be awesome.

zemapavara · 10-02-2021, 02:59 PM

when you need to buy tires for rims you gone use front 225/45 R18 , back 255/40 R18.
I will not recommend run flat tires is to heavy and not comfortable

chowser51 · 10-02-2021, 03:52 PM

Guessing your car had the staggered fitment option.

Itogliano · 10-03-2021, 11:23 AM

Quote:

Originally Posted by chowser51

Guessing your car had the staggered fitment option.

If it came staggered from the factory the door jamb sticker wouldn't have the 205 tire size info

chowser51 · 10-03-2021, 04:00 PM

It could have been a dealer swap when it was originally sold or the last owner added them.
Check to see if the "WHEEL" width is the same from front to rear. Last owner could've just stretched the rear tires on. Best to buy appropriate tires to fit the wheels.

My car came with a square setup, it is an xdrive also so I just winter tires on the 18" factory wheels and for summer I used a staggered 19" setup.

09-16-2021, 10:30 AM	#1
Prowller Registered 0 Rep 3 Posts Drives: 2017 F30 LCI Join Date: Jul 2021 Location: Romania iTrader: (0)	Tire dimensions Noob Question Hey guys, I recently bought a BMW 2017 Series 3 LCI and wanted to buy a pair of run flat tires for the cold season to use with my current r18 rims however, I'm noticing a difference between what the car's certificate has written on it (205/60 ) and the dimensions I have on the current tires, front 225/45 R18 , back 255/40 R18. Now, I'm a total noob and not sure what to get in terms of dimensions because i have the dimensions on paper, but in real life I got something else (just bought the car 2 months ago) so given that it's also Xdrive, is it a requirement for the tire to be larger on the back or? Any help or article that can explain it would be awesome.
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10-02-2021, 02:59 PM	#2
zemapavara New Member 8 Rep 10 Posts Drives: 330e Join Date: Oct 2021 Location: Norway iTrader: (0)	when you need to buy tires for rims you gone use front 225/45 R18 , back 255/40 R18. I will not recommend run flat tires is to heavy and not comfortable
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10-02-2021, 03:52 PM	#3
chowser51 Colonel 2025 Rep 2,808 Posts Drives: F33 430 and F39 M35i Join Date: Feb 2009 Location: Cleveland, OH iTrader: (3) Garage List 2018 BMW 430i xDrive [0.00]	Guessing your car had the staggered fitment option.
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10-03-2021, 04:00 PM	#5
chowser51 Colonel 2025 Rep 2,808 Posts Drives: F33 430 and F39 M35i Join Date: Feb 2009 Location: Cleveland, OH iTrader: (3) Garage List 2018 BMW 430i xDrive [0.00]	It could have been a dealer swap when it was originally sold or the last owner added them. Check to see if the "WHEEL" width is the same from front to rear. Last owner could've just stretched the rear tires on. Best to buy appropriate tires to fit the wheels. My car came with a square setup, it is an xdrive also so I just winter tires on the 18" factory wheels and for summer I used a staggered 19" setup.
	Appreciate 0 Quote