[iki4life]

I have a 2013 328i SportLine with OEM 397 Wheels and current OEM tires measuring 225/45R/18, squared, pirelli run flats.

What is a safe, wide measurement I can fit onto my 397 wheels? I need to get all 4 tires replaced, and Im looking at all-season tires but must be affordable and and reliable. I dont need the cream of the crop tire or anything that has superb performance.
Just a wider fit, affordable, reliable, and safe.

Thanks for your help, I'm new to this.

[ATs335Xi]

245/40/18 is the way to go. Maybe 245/45....

[Budget M3]

Originally Posted by ATs335Xi

245/40/18 is the way to go. Maybe 245/45....

OP should be advised that 245/40r18 is a bit smaller in circumference than stock, so the speedo will read faster than you are actually going and the odo will rack up miles faster. 245/45r18 will be larger around than stock so will have the opposite effect--will read slower than actual speed and odo will be slower.

If you own your car then probably not a big deal. If you lease, then it could be a consideration.

[iki4life]

Originally Posted by Budget M3

OP should be advised that 245/40r18 is a bit smaller in circumference than stock, so the speedo will read faster than you are actually going and the odo will rack up miles faster. 245/45r18 will be larger around than stock so will have the opposite effect--will read slower than actual speed and odo will be slower.

If you own your car then probably not a big deal. If you lease, then it could be a consideration.

thanks for the input, but id like to know why would the speedometer and odo be faster on a 245/45/18 as opposed to a 225/45/18? The circumference for those 2 is the same right? the only difference is the width, which should have no effect on the speedometer/odo.

i own the car so it doesnt really matter.

and lastly, whats the better choice between a 245/40/18 and 45?

[iki4life]

lastly, which tire should I buy? Im replacing the OEM Pirelli runflats, and looking for something good that doesnt break the bank.
thanks.

[jinnrice]

Originally Posted by iki4life

thanks for the input, but id like to know why would the speedometer and odo be faster on a 245/45/18 as opposed to a 225/45/18? The circumference for those 2 is the same right? the only difference is the width, which should have no effect on the speedometer/odo.

i own the car so it doesnt really matter.

and lastly, whats the better choice between a 245/40/18 and 45?

Tire circumference is not the same from 225/45 to 245/45. Goto tire rack and check the specs of the tire you are buying. Too much to explain.
Or try this site.
1010tires.com.

If your car is dropped a little then 245/40 would be better looking. 245/45 would be better for pot holes.

[Budget M3]

Originally Posted by iki4life

thanks for the input, but id like to know why would the speedometer and odo be faster on a 245/45/18 as opposed to a 225/45/18? The circumference for those 2 is the same right? the only difference is the width, which should have no effect on the speedometer/odo.

i own the car so it doesnt really matter.

and lastly, whats the better choice between a 245/40/18 and 45?

As jinnrice said, they are not the same diameter. Stock size is 25.97 inch diameter. 245/40 are a little smaller around and 245/45 are a little larger, so the 40's will have to make more revolutions per mile over the same actual distance, and the 45's will have to make fewer revolutions.

1010tires.com is a very good tire size calculator. Best choice is up to you, but I always prefer a larger diameter (up to ~2%) when changing tire sizes. it helps to correct for the notoriously optimistic BMW speedo from the factory

[.BMW.]

Originally Posted by Budget M3

I always prefer a larger diameter (up to ~2%) when changing tire sizes. It helps to correct for the notoriously optimistic BMW speedo from the factory.

+1

[iki4life]

Im about to pull the trigger on the Michelin Pilot Sport A/S 3+ ....Size 245/40zr/18....to fit onto my OEM 397 squared wheels.

Good choice????

Im coming from the OEM Pirelli RunFlat 225/45r/18 tires.

[ATs335Xi]

Definitely sounds like an improvement to the RFTs...

[iki4life]

Originally Posted by ATs335Xi

Definitely sounds like an improvement to the RFTs...

took your advice, thanks. Im just wondering how it will look....i hope the new tires aren't too tucked in, and look flush as possible, as i prefer a flushed/beefy look.

[Regisss]

Today I bought OEM 397 wheels and I am confused about tyres... Original size is 225/45 R18, but tyres looks small... would 235/45 be better?

Does anyone have photos of OEM 397 wheels with 235/45 tyres? Please share them!


I have F30 320d sportsline with M sports suspension.

[iki4life]

Originally Posted by Regisss

Today I bought OEM 397 wheels and I am confused about tyres... Original size is 225/45 R18, but tyres looks small... would 235/45 be better?

Does anyone have photos of OEM 397 wheels with 235/45 tyres? Please share them!


I have F30 320d sportsline with M sports suspension.

most people go with size 245/40/18
I have 397 wheels also. once they are installed ill post a pic

[Regisss]

Originally Posted by iki4life

most people go with size 245/40/18
I have 397 wheels also. once they are installed ill post a pic

It would be nice you have 245 or 235?

[iki4life]

Originally Posted by Regisss

It would be nice you have 245 or 235?

245