08 335i Rim size change.

Does anybody know if the rim sizes are different from front to back? I know the tire sizes are different. I was wondering if I could go with the same size tire on front to back. Or do I need to stick with the different tire size ?. The dealer told me that all 4 of my rims are bend and 700 bucks a piece to fix them. I find that hard to believe that all 4 are bend. So it's a lot cheaper to go with aftermarket wheels. At this point I'm looking for new rims and non run flat tires.

I went w/ Apex 17" Arc-8 wheels on my E92 w/ 255/40's all 4 corners. Unless roads are glass-smooth where you live, I think it's entirely plausible the rims could be bent - the low profile tires commonly used on recent-era bimmers easily open up the potential for rims getting bent. However, if you doubt your dealer's word, any tire shop should be able to verify if you have a bent rim.

Tire Rack offers the advantage of a set already mounted, balanced, & ready to go on the car, if they have a wheel you like. I prefer the lightest wheels possible that are reasonably priced, plus, the easier to clean, the better. Lots of options there, although TR doesn't carry Apex wheels.

I went with this for a spare -

http://www.ecstuning.com/BMW-E92-335is-N54_3.0L/Search/SiteSearch/Spare_Tire/ES2535349/

There's no reason you can't run the same size tires on all 4 corners, the typical constraint is the widest possible wheel & tire combo you can run on the back (typically a good bit wider than the stock rear size) won't fit the front without rubbing something. For the non-M models, I think most stand a pretty good chance the stock rear width tire will fit the front without much of an issue.

Thank you guys for the great Info. MGarrison-I like that spare, a little pricey but nice. I will look into Tire Rack tires already mounted with all 4 tires the same as the stock rear width. I may put the rear one I have now up front to check for rubbing/clearance. I believe I was told to get a front end alignment after I get all new tires, do you guys agree?

Removing & re-installing wheels normally wouldn't affect alignment. However, if you're getting an uneven wear pattern on your current tires, that might indicate an alignment issue, or something worn or out of spec. If that's why your dealer is suggesting an alignment, obviously it's better to resolve it rather than have the same issue prematurely wear-out new tires.

A normal wear pattern on the rears, barring a tire that can be rotated around the car or flipped on a rim, will have the inside edges worn more than the rest of the tire, probably about the same wear on both rears for any given mileage. The fronts, typically, should be evenly worn across the width of the tire.

Not a bad idea to check clearance by putting one of the rears on the front - might be a good idea to call the Tire Rack when you have some wheels/tires picked out, they should be able to offer advice on fitment, etc. Tire Rack is typically conservative on their fitment recommendations, so if they say it fits, you can be pretty confident it will.

Thank You MGarrison for all your help. Why does BMW put different size tires front to back on these years? I priced it out on TR and it really adds up. You have to add in the tire sensors at $47 a piece because I was ordering the tires already mounted. I guess I would be better off doing that then going through the trouble of getting the old sensors and having them installed.

Any suggestions on what tire to go with in a 255/35 18?

Finally! My reply box is back - freakin' browser wonkiness!

First, getting new pressure sensors is a good idea - the batteries don't last forever, so a new set of those now will save you having to pay to have tires dismounted, re-mounted, & re-balanced, just to replace dead pressure monitor sensors (I'm not sure if the battery is replaceable, but I have the recollection from my wheel/tire purchase a few years ago that they're not).

BMW sticks narrower tires on the front to make the car inherently understeer (front end pushing) more, (quite typically, a lot more), before transitioning (which could be a somewhat gradual or startlingly sudden transition) to oversteering (back end stepping-out/sliding).

By setting up the car this way, if the car is starting to move towards going too fast through a turn, the driver (hopefully) will have early enough feedback indicating that the grip situation is sliding right along towards an "Oh $h*t" moment, and accounting for the typical driver's reaction, have the typical driver's response result in avoiding reaching the too-late "brown shorts" post-accident stage.

Translated, that means that if someone's unexpectedly sliding through a turn, or ending up going through a turn too fast, for most drivers, having the front end losing grip before the rear means they'll sense that, and, realizing that they're going to fast, will lift off the gas (at least) and/or then go for the brakes. If the car is understeering, this is the correct response, because lifting &/or braking will transfer some weight to the front tires, hopefully re-establishing grip, & control. Having the back end slide out, particularly for drivers unfamiliar with how that feels, or un-practiced with skid reaction & recovery, can be panic inducing for the driver, meaning they will lift & jam the brakes, completely unloading the rear of the car and inducing it into a spin, with no hope of saving it or keeping things under control at all.

More power to Carrie Underwood, but regardless of how much faith someone has, it's probably a bit hopeful to expect Jesus to take the wheel in an emergency situation & miraculously react to keep one's butt out of a sling. Not that it's not possible, but I'd say much better to give Jesus some assistance in this process by pro-actively responding appropriately (which takes understanding what to do, and then practicing, if possible). By biasing the handling balance towards substantial understeer before going to oversteer, plus all the electronic faeries intervening additionally, BMW would be striving to minimize for most drivers the frequency of the "Oh $h*t"/Jesus moments experienced out on the road, even when they purposely get in over their heads.

However, given the uber-sticky tires they're throwing on most models these days are down to tread-bars on the rears by 16-20k miles, and being unable to rotate the tires around the car to even-out wear, means owners are facing an expensive run-flat tire purchase within a fairly short period of time. In the somewhat less-litigious world of times past, many BMW models had the same size wheels and tires at all 4 corners, and presumably it was felt that the task of keeping the car under control in dynamic situations would be the charge of the driver, for better or worse.
These days, obviously less so.

As for tire recommendations - generally, I'd say consider your usage of the car - for instance, do you really _need_ 140 treadwear-rated tires like what it probably came with that will be worn down to the nubbins sooner rather than later? Or do you prefer the lateral grip, shorter stopping-distances, and performance aspects that come along with sticky gumballs, despite the expense of more frequent replacement? Drive in snow? Look at the tread pattern - maybe you need something more pedestrian or M&S rated for winter traction. Anyway - tires, in every aspect, reflect a series of compromises on the designers part to meet a specific goal. Mega-performance summer tires don't cut it in winter, for instance; some can't even be driven on if the air temp is below freezing!

Assuming you're not planning to emulate F1 or rally drivers every time you push the start button, I'd say look at TR's Ultra-High Performance All-Season category (minus run-flats) - I'm partial the the Bridgestone RE970 AS or Conti Extreme Contact DWS, although I'd go for the Bridgestone with its slightly lower UTQG (treadwear rating). Remember that whole bit about lateral grip & stopping distance - Higher UTQG number, typically harder tread compound, translating to longer tire life, but also less cornering & stopping grip (typically - experts & presumably the TR sales guys should have more specific insight on any given tire). The Yokohama Advan Sport A/S doesn't look bad, although I'm not sure that tread pattern looks quite up to the task of much "spirited" driving - again, looks of treadwear pattern is a pretty subjective judgment, so a conversation w/ someone @ Tire Rack might help guide you. If you're in a southern climate, snow performance less of an issue, so you can look the tire for rain/water dispersal, which opens things up beyond the a/s all-season category.

I'm running the Conti DWS on a 540i Sport and am pretty happy with them. They followed Advans that were disappointing. The Bridgestones are kinda noisy but grippy. These are Not to be confused with 140-200 track/street skins but, they really aren't bad and they do well year round.

We had a 335xi with staggered 18s. Changed to a 235 square set-up that worked very well. I'm reasonably sure 255s would fit (unless you lower the suspension substantially). I've seen bigger but usually with a little rub-a-dub dub on a street driven car. Rim width/offset get critical as the size goes up.

Thank You guys for all the Info. It seems I have a lot to think about. I don't plan on taking out by 335I in bad weather,that's why I kept my Cherokee with a locker up front and factory posi in the back. But I do plan on driving it in the winter some, maybe on cold days. So I would need a tire that would grip the road in cold weather. Maybe it would be a good idea to talk to someone at TR.

I Rotated the rear 255's up front to test it out. I found the 255 is so close to the strut tower that I could not even get the tip of my finger between the tire and the strut. I did drive it and did not hear/feel anything. But that is too close for comfort. I think I will go with the 235 on all 4 sides. I measured the tire width from the 225 front to the 255 back and there was about 1/2" difference.I could not tell a height difference between 40r18 and 35r18 by just eye balling it and with a tape measure.Just thought I would throw that out there. I'm getting ready to buy new tires and rims. I may keep one of my old tires/rim as a spare. and sell off the other 3 as spares if anybody needs one.

When you look at tires, be careful of aspect ratio. The aspect ratio of the tires will make a larger diameter difference than you might think. Between /35, /40, /45, nearly an inch each step. And the tire weight will also increase with taller tires, up to 3 pounds per step, per 235x18" tire.
Tire diameter potentially affects more than just clearance. Ride comfort and handling can be greatly affected. Taller tires (typically) = more ride comfort but diminished handling response and vice versa. You will determine the balance you want.
Speedometer/odometer accuracy will be affected if you change tire diameter significantly (this is the easiest way to correct the factory BMW speedometer error).

Remember, the shorter the tires you run, the more susceptible to damage your rims will be. They look gooood but ...
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