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[FSociety]

Everyone with XI model here, do you guys upgrade to square setup or staggered setup ?

I am wondering what to do with my 328xi came with 205/55-16 square, but I know I should be doing 225-45/17 square or 225/40-18 square, but tirerack recommends 225/45 front 245/40-17 rear or 225/40 front 255/35/18 Rear even when I choose XI model on their list wouldn't that defeat the purpose of AWD handling ?

Also, how do I know what 18x8 ET32 5x120 is for the fitment that I am looking for?

I am still debating on going OEM (used) or getting brand new replicas from a local place where I can check them out and at least go for warranty.

Thanks

[zipstic]

I run a square 225/40/18 setup in the winter and a staggered 235/35/19 front 265/30/19 rear setup in the summer.

Running a staggered setup doesn't defeat the purpose of AWD; however, you will get slightly more understeer. For me, I don't track my car at all and I don't notice any difference in understeer - you'd only really notice this on a track. If you end up going with a staggered setup you want to make sure that the revs per mile front to back are within 5. Tirerack has this info under the specs tab for each tire.

You can go with 18x8 ET32 or you can go with other options. I have 18x8.5 ET35 and 19x8 ET35 F and 19x9 ET38. It just depends on what you're looking for.

[drfrink24]

I was considering running a staggered setup, but didn't want to remove the ability to rotate tires, so I went with square. However, I have since learned that rotating tires on these cars doesn't really decrease tire wear, infact, I believe there was a post showing that BMW doesn't even recommend rotating tires.

[FSociety]

I think to be safe with AWD I should go with square setup right?

[obert]

Some if not all XI come with stagger set up so I think either way you will be fine?

My 335xi came stock with stagger.

[obert]

Originally Posted by ROBNYC

My 328xi came with 205/55 R16 all around but I see tirerack is recommending me 225/45 17 front 245/40 17 rear or 225/40 18front 255/35 18 rear ..

My cousin's 328i 2011 came with 225/45 17 all around I thought RWD was suppose to be staggered

Not sure but my 08 328i and my 08 335xi both came staggered.

[Gary@TireRack]

There are staggered and non-staggered setups that come factory on the rear-wheel drive E90 cars.

There are staggered and non-staggered setups that come factory on the all-wheel drive E90 cars.

[jcarv20s]

Sports Package with Premium wheels will come staggered doesn't matter if it's an Xi or I. Otherwise square. You can run either with 17+'s rims.

[wdeerfield]

its best to go with square if you want to rotate and get the most life out of your tires. I run 235/40/18 on 18x8.5s with 10mm/15mm spacers front and rear.

[afadeev]

Originally Posted by ROBNYC

Will 225/45-17 Front 245/40-17 Rear or 225/40-18 Front 255/35-18 Rear fit without any rubbing or spacers?

Rob,

Generally, there is no upside to staggered setup as it will:
a). prevent front/rear rotation to even out the wear (front and rear tires DO wear differently!);
b). introduce more understeer (makes BMW lawyers happy; performance drivers unhappy; 95% of the drivers can't tell the difference).


Wheel size, width, and offset have as much to do with rubbing as the tire size.
In the US, E90s iX cars came with 2 common wheel setups:
square: 225/45-17 [on 17x8 ET34 wheels]
staggered: 225/40-18 [front: 18x8 ET34] and 255/35/18 [rear: 18x8.5 ET37]

There are also 19" factory setups out there (way more expensive tires!), but the thing to note is that even with the staggered OEM setup, the rolling diameter of the 225/40-18 (25.09" diameter) and 255/35/18 (25.03" diameter) tires is within 0.2% of front vs. rear.

That's a very important consideration on iX cars.
The difference of much more than 1% (or 0.25") in rolling diameter front vs. rear is liable to cause issues with DSC and the transfer case).

Your <225/45-17 Front 245/40-17> combo will introduce exactly 1% difference in rolling diameter, putting you at the margin of trouble.
Your <225/40-18 Front 255/35-18 Rear> combo is stock, and will work great with DSC. Whether it will rub or not will depend on the wheels !

Originally Posted by ROBNYC

Why didn't u get 235/50 if u were going to use spacers? or 225/40 without spacers according to tirerack

Spacers are likely there to compensate for wrong (too much) offset. Or for cosmetic reasons (some people like to see there wheels "stick out").

235/50 tires on 18" wheels would give you stupid tall (27.25") tire+wheel combo, which is 2.25" taller than stock. Firstly, it will likely rub all over. Secondly, the extra-tall sidewall will destroy the handling with excessive sidewall flex. Lastly, it will increase the effective gearing ratios and slow down the acceleration. Bad all around.

235/40-18 combo, on the other hand, is just 1.69% taller than stock (at 25.4"). And being square, is just fine with DSC.


All of the above should already be giving you a headache in deciding how to proceed. And that is before you even started looking at tire prices ;-).
If you want to keep it simple, either:
a). stay with stock sizes (see above);
b). stay square at near OEM rolling diameter (google for tire size calculators).


For me, 18x8.5" ET35 wheels with 235/40-18 Michelin Pilot Super Sports all around works like a charm.

YMMV,
alex f

[wdeerfield]

Originally Posted by ROBNYC

Thanks so much , so I want to go with the 17 or 18 square setup. I think 225/45-17 all around will be ok? And 225/40-18 will be ok square setup too ? I'm going by the tire-rack recommendations. You have 235/40-18 I'm guessing with spacers?

I'm looking at the Continental ExtremeContact DWS or Bridgestone RE970AS .. Debating if I should go 17 or 18

The Extreme Contact DWS is a very nice tire. You can go with the 225/40/18 just fine. I just wanted a little wider tire for a little more meat (i know, 10mm, but still). Also, that was the recommended sizes when i had my e46. The spacers were added to put it flusher with the fenders for a filled out look. They had an et40 which was a hair high for the E90XI as it was millimeters from my front struts and i didnt want to chance it. I could have sold the rims and got better fitting ones but opt'd to just space them out how i wanted. Sometimes higher offset wheels allows you to play with spacer thickness if you want to. If you are going OEM 18s, i would personally get four REAR rims in et 37 and go with either of the two tire sizes mentioned (225 or 235 in a 40 sidewall)

[wdeerfield]

Originally Posted by ROBNYC

Thanks,
Yea looks like I'll be going with either 225/45-17 or 225/40-18 (Since the 235/40-18 would require spacers right? ). After my research I am not buying any rims from tirebuyer (they all s**k are heavy as hell), so waiting to hear back from my friend's friend to see how much discount will I be able to get on 17 or 18 tires.

I chose Bridgestone Potenza RE970AS Pole Position 1st choice, Conti DWS 2nd choice, and Bridgestone Potenza RE960AS RFT 3rd choice. I'll be looking locally for some OEM rims as I don't want to spend a fortune on light-weight rims since they seem to cost the most.

The tire size isnt what causes need for spacers, its the offset of the rims. higher offset means they sit further in (closer to the strut) lower offset means they will stick further away from the strut.

[afadeev]

Originally Posted by ROBNYC

Thanks so much , so I want to go with the 17 or 18 square setup. I think 225/45-17 all around will be ok? And 225/40-18 will be ok square setup too ? I'm going by the tire-rack recommendations. You have 235/40-18 I'm guessing with spacers?

18x8.5 wheels for me, 35mm offset. No spacers.
235/40-18 Michelin Pilot Super Sports on all four corners.

www.tirerack.com is a good source.
Not all 17" wheels clear 335i brakes, but TireRack (supposedly) tested them and only sells the ones that fit.

Originally Posted by ROBNYC

I'm looking at the Continental ExtremeContact DWS or Bridgestone RE970AS .. Debating if I should go 17 or 18

Personally, I would not buy either one of those (or for that matter any other All Season tire) if the goal is to achieve maximum traction in either summer or winter. For summer tires, Bridgestone RE11's or Michelin Pilot Super Sports would be far superior.

But if you live in NYC and need to drive in the winter, All Seasons are a reasonable compromise. Or better yet, get a set of dedicated summer and a a separate set of winter wheels and tires (my choice).

YMMV,
alex f

[wdeerfield]

Originally Posted by afadeev

For summer tires, Bridgestone RE11's or Michelin Pilot Super Sports would be far superior.

But if you live in NYC and need to drive in the winter, All Seasons are a reasonable compromise. Or better yet, get a set of dedicated summer and a a separate set of winter wheels and tires (my choice).

This site loves to push the PSS but not everyone drives in a manner that would require such a tire or want to replace tires every 10k at over $300 a tire. I daily commute with mine and have ContiProContacts and they handle everything i encounter on a daily basis.

[Fun w/N54]

What is your wheel width? 10k miles later and very happy with the DWSs on factory 188 style wheels, with 245/40/17 square.