[T4NZ4NIT3 335i]

Originally Posted by floydarogers

I disagree about 225 & stretched. 225 is the STANDARD width for E9x and F3x tires, and 8" is the STANDARD width for wheels on same. And 8.5 is the standard rear width for a staggered set with 255 rear.

Better to say you like the APPEARANCE of slightly bulging tires.

You need to read up on the terms measured rim width and section width and correlation between the two. 225 may be the "standard" width for e90 and f30 on 8 inch rims as BMW sells it but doesnt mean it is the ideal or the design rim width for a 225 width tire or 225 is the ideal width tire for that rim width.

Also the ideal rim width for a 255 tire is not 8.5 or as you call standard (sure BMW sells it that way). Its 9 inch. How can 225 be standard for 8 and 255 for 8.5? What is the standard rim width for 235 or 245 width tires then?

There is a slight bulge on 8.5 with 255, I know because I run 255 square on 18x8.5. I wanted 9s but couldnt find rims with the right offset and I hate the thought of spacers.

http://www.tirerack.com/tires/tirete...jsp?techid=199


Measured rim width for xice 225/45/18 is 7.5 inch and it is 8inch for 235/45/18 and I wouldnt call the appearance bulging. It is bulging if you mount 235/45/18 on the narrowest allowable width for the tire: 7.5inch

http://www.tirerack.com/tires/tires....odel=X-Ice+Xi3

With winter setups its better to not go stretched to avoid pothole/curb damage and better to go with conservative offset/narrower rims so wheels are nicely tucked in and dont sling salt,slush and whatnot all over the doors,rear quarterpanel/bumper.

[metallicpea]

If you don't have the upgraded brakes, I would run 17x7.5 wheels all around with 225/50x17 tires. If you really want to run 18" or have the larger brakes and need to, run 18X8 with 225/45x18.

The whole point of running snow tires is to get the best snow and ice traction. I don't see a point in sacrificing snow and ice performance to run something that looks better. Besides, they don't need to be on the car that long anyway and the car is always dirty in the winter, so it never looks good until the salt is gone.

Makes me appreciate my summer set even more when they go back on.

[floydarogers]

Originally Posted by T4NZ4NIT3 335i

You need to read up on the terms measured rim width and section width and correlation between the two. 225 may be the "standard" width for e90 and f30 on 8 inch rims as BMW sells it but doesnt mean it is the ideal or the design rim width for a 225 width tire or 225 is the ideal width tire for that rim width.

For the 225/45R18 Michelin PS2 ZP, the measured rim size is 8", and it fits on 7.5-9. There is no mention of "ideal" on tirerack, so "measured rim" is what I'm going by, as it's characteristics in tirerack's explanation match what you seem to want to call "ideal rim size". Please don't invent terms that are not standard, and confuse things.

[T4NZ4NIT3 335i]

Originally Posted by floydarogers

For the 225/45R18 Michelin PS2 ZP, the measured rim size is 8", and it fits on 7.5-9. There is no mention of "ideal" on tirerack, so "measured rim" is what I'm going by, as it's characteristics in tirerack's explanation match what you seem to want to call "ideal rim size". Please don't invent terms that are not standard, and confuse things.

read the thread title..its for winter tires. The measured rim width for xice xi3 for 225/45/18 is 7.5. Why are you posting numbers for Ps2 ..a summer perf tire?The measured rim width changes with tire type..sidewall profile and even manufacturer and construction. Winter tires run narrower by default to aid deep snow traction. Tread width us a more accurate stat to go by than section width when choosing rim width because tread width vatries between manufacturers even if the section width is the same. PSS for eg run super wide and pirellis are known to run narrower.

[floydarogers]

Originally Posted by T4NZ4NIT3 335i

read the thread title..its for winter tires.

Hey, you were the one (in post 23) to shift to BMW tire wheel combinations, which are de-facto summer tires. I was just giving an example from that set that counters you "ideal" claim.

A tiresome OT adventure. I really gave the OP my advice on sizing winter tires way back at the beginning; nothing in this side discussion changes the correct advice I gave there.

[335BOY]

Originally Posted by COKen

While narrow tires do go through deep snow better than wider tires, both tires will have the same pressure per square inch if they are filled with the same air pressure. The weight per square inch of any tire is always equal to the air pressure in the tire. Any tire inflated to 32 pounds per square inch, for example, presses down on the pavement with 32 pounds per square inch. The weight of the car is counter balanced by the air pressure in the tires on the surface so the pressure per square inch will be the same no matter how wide the tire. The shape of the contact patch is wider for the wide tire, but shorter. The shape for the narrow tire is longer but narrower. But both will have the same contact area. We keep hearing that you should use narrow tires for your winter tires, which is true if you will be driving in deep snow, but for most of us it really doesn't matter, because most of us drive in areas where the roads are plowed, or have enough traffic so that any snow is packed down.

I agree. I always go OEM size with winters as roads are rarely covered in deep snow and I'm on cold clear roads mostly so narrower tire will be worse.

[335BOY]

Originally Posted by T4NZ4NIT3 335i

You need to read up on the terms measured rim width and section width and correlation between the two. 225 may be the "standard" width for e90 and f30 on 8 inch rims as BMW sells it but doesnt mean it is the ideal or the design rim width for a 225 width tire or 225 is the ideal width tire for that rim width.

Also the ideal rim width for a 255 tire is not 8.5 or as you call standard (sure BMW sells it that way). Its 9 inch. How can 225 be standard for 8 and 255 for 8.5? What is the standard rim width for 235 or 245 width tires then?

There is a slight bulge on 8.5 with 255, I know because I run 255 square on 18x8.5. I wanted 9s but couldnt find rims with the right offset and I hate the thought of spacers.

http://www.tirerack.com/tires/tirete...jsp?techid=199


Measured rim width for xice 225/45/18 is 7.5 inch and it is 8inch for 235/45/18 and I wouldnt call the appearance bulging. It is bulging if you mount 235/45/18 on the narrowest allowable width for the tire: 7.5inch

http://www.tirerack.com/tires/tires....odel=X-Ice+Xi3

With winter setups its better to not go stretched to avoid pothole/curb damage and better to go with conservative offset/narrower rims so wheels are nicely tucked in and dont sling salt,slush and whatnot all over the doors,rear quarterpanel/bumper.

Whats wrong with spacers?