# Same size tires on staggered rims?



## Bremen Ben (Sep 1, 2008)

Is it ok to put same size tire on all four rims even if the wheels are staggered set? After much deliberation I now decide to use my 18 inch as winter wheels; it's 245/40-18 front and 275/35-18 rear staggered set. Only problem is, my dealership can't find the Bridgestone Blizzak by now for the 275/35-18 rears. 

As an alternative, the dealership told me the 245/40-18 rubber can also be mounted on the rear wheels even though the rear wheels are wider. Basically I would have 245/40 on all four corners.

Does anyone have this type of set up? Would there be any problem with mounting narrower tires on wider wheels?


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## woody underwood (Feb 9, 2004)

You better call Tire Rack about that...doesn't sound like a good idea to me.


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## Norm37 (Jun 28, 2008)

woody underwood said:


> You better call Tire Rack about that...doesn't sound like a good idea to me.


:thumbup:

http://www.tirerack.com/about/contact.jsp


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## Fast Bob (Jun 4, 2004)

245/40s would work fine....just make sure to put the *rear wheels on the REAR*....(the offsets are different F/R....)


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## Bremen Ben (Sep 1, 2008)

Thanks for the feedbacks. Fast Bob I take it you mean as long as the rear rims are not mistakenly put on the front, it will be ok for the wider rims to accept narrower tires?


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## Bremen Ben (Sep 1, 2008)

Found some more confirmation on 1010tires and tirerack; tires do fit on different width rims as long as the rim width is within the approved range. My rear rims are 9"x18, and the 245/40-18 Blizzak has the approved rim width range of 8" to 9.5". So I think I should be fine putting it on the rear. Might increase the ride stiffness, but I will see how it goes.


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## WGMc (Aug 3, 2009)

Would the tire height be slightly different on the wider rim? It would definately change how the sidewall fits the rim and you may have a situation that the rear tires are shorter than the front. That probalby wouldn't be a good driving experience. I wouldn't do it.


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## cmybimmer (Sep 16, 2008)

Aside from performance and fitment, I think itll look funny :dunno:. the front tires will be nicely fitted with some nice sidewall, while the rears will have a stretched look.


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## Fast Bob (Jun 4, 2004)

WGMc said:


> Would the tire height be slightly different on the wider rim? It would definately change how the sidewall fits the rim and you may have a situation that the rear tires are shorter than the front. That probalby wouldn't be a good driving experience. I wouldn't do it.


You don`t know WTF you`re talking about....let`s just leave it at that....


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## WGMc (Aug 3, 2009)

Fast Bob said:


> You don`t know WTF you`re talking about....let`s just leave it at that....


Oh come on Fast Bob tell us WTF you know. Did you notice I asked "would" the height be different on a wider rim.

Ben, why not call BMW and ask what they say about your tire question.


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## Fast Bob (Jun 4, 2004)

WGMc said:


> Oh come on Fast Bob tell us WTF you know. Did you notice I asked "would" the height be different on a wider rim.
> 
> Ben, why not call BMW and ask what they say about your tire question.


I`ll break it down for you....a 9-inch rim is 225mm wide between the mounting flanges....a 245 tire`s maximum tread width is *still* 20mm (or 3/4 of an inch) wider than the rim....the tire`s mounting bead is usually around 1 inch inboard of max tread width after mounting & pressurization, giving you a very acceptable tire-width-to-rim-width ratio (only 1/4 inch difference).
That`s WTF **I** know....


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## Bremen Ben (Sep 1, 2008)

Appreciate the information. By the way I did talk to the dealership originally; it is the parts guy who told me that he was told by his "tire rep" that the setup would work. I also just called BMWNA as Greg suggests. They say they would refer the question to the individual dealership. 

I am going have the tires put on; will give an update in a few days to let everybody know how it works out.


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## Fast Bob (Jun 4, 2004)

Bremen Ben said:


> Appreciate the information. By the way I did talk to the dealership originally; it is the parts guy who told me that he was told by his "tire rep" that the setup would work. I also just called BMWNA as Greg suggests. They say they would refer the question to the individual dealership.
> 
> I am going have the tires put on; will give an update in a few days to let everybody know how it works out.


Unfortunately,the current state of BMWNA is nothing more than a bunch of corporate paper shufflers, certainly not a fountain of technical knowledge, like they used to be 25 years ago....there`s been a rather extreme paradigm shift at BMW over the years....seems they`re more concerned with chipping away at the Lexus/Infinity/Acura end of the market, and developing a "BMW for every driveway" mentality, as evidenced by the proliferation of new models....


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## WGMc (Aug 3, 2009)

Fast Bob said:


> I`ll break it down for you....a 9-inch rim is 225mm wide between the mounting flanges....a 245 tire`s maximum tread width is *still* 20mm (or 3/4 of an inch) wider than the rim....the tire`s mounting bead is usually around 1 inch inboard of max tread width after mounting & pressurization, giving you a very acceptable tire-width-to-rim-width ratio (only 1/4 inch difference).
> That`s WTF **I** know....


Thanks for confirming that rim width "does" change tire height and aspect ratio; for a minute I thought you were disagreeing with me :rofl:

Will this slight difference change the handeling or performance of the car....apparently the BMW engineers think so or they wouldn't have upsized the rear tires for those of us that have staggered setups....but WTF do they know. From your last post to Ben, it looks like you don't care much for what BMW thinks either and that is okay. We all have an opinion and you and I have stated ours.

BMWNA is not going to give a recommendation that differs from the factory settings, so they defer and say "ask the tire rep". It releases them from liability and that is truely all they are interested in.

Ben, in reality it probably won't make much difference. Bob has supplied you with the numbers so you have to make the decision. My last suggestion would be to buy the tires locally instead of through tirerack. If you go to a local dealer and they mount the tires and you decided....."they just don't look right" you can have them dismounted and changed before you leave the dealership. If you order them online you may be stuck with 2 tires you don't want. Good luck.


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## djfitter (Sep 12, 2007)

WGMc said:


> *Thanks for confirming that rim width "does" change tire height and aspect ratio;* for a minute I thought you were disagreeing with me :rofl:
> 
> Will this slight difference change the handeling or performance of the car....apparently the BMW engineers think so or they wouldn't have upsized the rear tires for those of us that have staggered setups....but WTF do they know. From your last post to Ben, it looks like you don't care much for what BMW thinks either and that is okay. We all have an opinion and you and I have stated ours.
> 
> ...


Where does Fast Bob say that?  He only mentions a "very acceptable tire-width-to-rim-width ratio (only 1/4 inch difference)."

dj


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## tturedraider (Nov 11, 2005)

WGMc said:


> Oh come on Fast Bob tell us WTF you know. Did you notice I asked "would" the height be different on a wider rim.
> 
> Ben, why not call BMW and ask what they say about your tire question.





Fast Bob said:


> I`ll break it down for you....a 9-inch rim is 225mm wide between the mounting flanges....a 245 tire`s maximum tread width is *still* 20mm (or 3/4 of an inch) wider than the rim....the tire`s mounting bead is usually around 1 inch inboard of max tread width after mounting & pressurization, giving you *a very acceptable tire-width-to-rim-width ratio (only 1/4 inch difference).*
> That`s WTF **I** know....


+1 - if you go to any tire manufacturer's website and check the specs on their tires they will give the range of rim widths each of their tires will fit. There is more than one rim width that a tire will fit. It's usually about a 1 1/2" range, e.g. a certain tire would fit a wheel 9" - 10.5" wide.


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## JimD1 (Jun 5, 2009)

WGMc,

I think FastBob gave up. The aspect ratio of a tire is not changed by the rim it is mounted on. Aspect ratio is just the ratio of the width of the tread to the sidewall height. In theory, I think you are thinking the diameter of the tire could change because the angle of the sidewall changes but the difference is so slight the better answer is that it makes no difference. In other words, changing the angle of the sidewall by the the 1/4 inch difference in position Bob calculated does in theory also change the diameter of the mounted tire but that ignores little factors like the sidewall is flexible (we are talking about radials so they are quite flexible) so it isn't really straight lines to start with and the diameter changes with tire wear and air pressure too. Air pressure changes both due to cold air pressure change and operating temperature. So in practice, if there is any difference at all in diameter, it is negligble.

The bottom line is that you can mount a tire safely on any rim that the tire manufacturer says it can be mounted on. I doubt anybody can tell a difference visually from the rim width. And it is totally safe with no functional impact. That is why the tire manufacturer says it is OK. Do you think they would OK it if there was added risk involved?

Jim


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## Bremen Ben (Sep 1, 2008)

I just have the tires mounted today. No problem at all. The rear wheels however have a slight gap between the edge of the wheels and the tire wall, whereas the front wheels look completely flush between the wheels and the tire wall. I will post a couple pictures tonight. Cosmetically that is not my preference if I had a choice. But it works.

The car also seems to handle less crisply in turning in and accelerating with these snow tires. With the oem Dunlop SP Sport 01 DSST RFTs the handling of the car feels very crisp; the tires really hug the road and give me very precise feedback of the road surface. I am missing that already. 

I do like the peace of mind driving in the snow for the rest of the winter though. Oh well until the Spring comes I will just have to endure...


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## Fast Bob (Jun 4, 2004)

Bremen Ben said:


> I just have the tires mounted today. No problem at all. The rear wheels however have a slight gap between the edge of the wheels and the tire wall, whereas the front wheels look completely flush between the wheels and the tire wall. I will post a couple pictures tonight. Cosmetically that is not my preference if I had a choice. But it works....


"All tires are not created equal"....even tires of the same size. A lot depends on the particular tire`s design & construction....a Dunlop Direzza Z-1 or BFG G-Force tire has a very large, blocky shoulder, and presents a very different profile compared to say, a Michelin PS2 or Pirelli P-Zero Nero.



Bremen Ben said:


> .
> 
> The car also seems to handle less crisply in turning in and accelerating with these snow tires. With the oem Dunlop SP Sport 01 DSST RFTs the handling of the car feels very crisp; the tires really hug the road and give me very precise feedback of the road surface. I am missing that already. ...


Snow tires are, by nature, soft compound, which is necessary for them to remain flexible in sub-freezing temps....the downside is that you now have a thick layer of wobbly rubber between your wheels and the pavement....kinda like driving on marshmallows. You almost have to "re-calibrate" your driving habits (on dry pavement), especially at speed....takes all the fun out of driving a BMW.... :-(

But, look for that Silver Lining....Spring is only 9 weeks away....


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## Bremen Ben (Sep 1, 2008)

Fast Bob said:


> But, look for that Silver Lining....Spring is only 9 weeks away....


LOL, you are such an optimist...!:rofl:

Here is how they look. The rear really looks "interesting" if looked closely.

Front (wheel flush with tire wall):









Rear ("why is your tire shrunk??" ):


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## JimD1 (Jun 5, 2009)

Nice camera work, very similar angle for both photos. I would agree the appearance at the tire to rim junction looks a little different. Do you think they look different from a more normal side view? My guess is that the angle you selected would maximize the ability to notice the tire is a little on the narrow side for the rim.

I am following this in part because I don't really like the idea of staggered sizes. I like to rotate to maximize tire life and it pretty much defeats that idea. I am curious to the back space comment somebody made earlier. If the front and back rims are different offset, you couldn't rotate without buying two new rims (which I would not do, I would go aftermarket to get 4 for the same price or less).

Jim


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## Bremen Ben (Sep 1, 2008)

Hi Jim you are right it will only look obvious if you stand close by and look at it from the angle. Additionally for the 99.9% of uninterested people they wouldn't notice any difference unless pointed out to them. 

From the side view the tire looks good (I can post a few side view pics later tonight); with the low profile aspect ratio of 245/40 the tires actually look every bit as sggressive as the oem tires. I was originally expecting (and dreading) four donut-looking tires on my car... 

I might not have most accurate information but I did ask the dealership about rotating the tires. They indicate it's possible since all four tires now are of the same size; I would just have to have the tires removed from the rims in order to rotate them.


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## djfitter (Sep 12, 2007)

Bremen Ben said:


> Hi Jim you are right it will only look obvious if you stand close by and look at it from the angle. Additionally for the 99.9% of uninterested people they wouldn't notice any difference unless pointed out to them.
> 
> From the side view the tire looks good (I can post a few side view pics later tonight); with the low profile aspect ratio of 245/40 the tires actually look every bit as sggressive as the oem tires. I was originally expecting (and dreading) four donut-looking tires on my car...
> 
> I might not have most accurate information but I did ask the dealership about rotating the tires. *They indicate it's possible since all four tires now are of the same size; I would just have to have the tires removed from the rims in order to rotate them.*


That is correct.  The downside is possible wheel damage and more wear on the tire bead each time. 

dj


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## JimD1 (Jun 5, 2009)

I only rotate tires by rotating the tire and wheel assembly. I wouldn't have the taken off the rims for rotation. I think the cost of rotating them with demount and remount and balance would be greater than any benefit provided. The dealer comment seems to reinforce that the back space is different.

Jim


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## Bremen Ben (Sep 1, 2008)

True, the dealership did mention I would only be able to rotate tires without the rims because of the rim offset. 

Curious enough when I brought up the potential for damaging the wheels and tire bead by regularly having the tires removed from the rims, the CA told me people do that all the time and he hasn't heard any problem yet. Assuming that is not exaggerated, could it be because of the equipment used by the dealership? 

I do notice the dealership is very careful about the work they do. The edge around the bolt holes on the rims shows no damage; I am very happy. I still remember the chips done to the wheels of my previous car by the careless people at a national brand name tire store doing a simple tire rotation.

Jim I assume you do you own tire swap?


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## Fast Bob (Jun 4, 2004)

JimD1 said:


> I only rotate tires by rotating the tire and wheel assembly. I wouldn't have the taken off the rims for rotation. I think the cost of rotating them with demount and remount and balance would be greater than any benefit provided. The dealer comment seems to reinforce that the back space is different.
> 
> Jim





Bremen Ben said:


> True, the dealership did mention I would only be able to rotate tires without the rims because of the rim offset.
> 
> Curious enough when I brought up the potential for damaging the wheels and tire bead by regularly having the tires removed from the rims, the CA told me people do that all the time and he hasn't heard any problem yet. Assuming that is not exaggerated, could it be because of the equipment used by the dealership?
> 
> ...


Mounting & dismounting of tires should always be kept to a minimum if possible....the possibility of damage to both rim and tire bead increases with every change.

Staggered setups *always* have a different F/R offset....
"Backspacing" and "Offset" are not one and the same (as many believe)....see attached diagram:


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## WGMc (Aug 3, 2009)

Ben, if you want to rotate the tires I would not rotate front to rear but rather side to side. I haven't researched your tires and may have missed it but if the tires are not directional you should be able to do that without any tire damage and that would keep the wider rim on the rear. If they are directional then dismount is the only way and that is a lot of trouble. Staggered setups are a pain, I have them on my car.


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## WGMc (Aug 3, 2009)

JimD1 said:


> WGMc,
> 
> I think FastBob gave up. The aspect ratio of a tire is not changed by the rim it is mounted on. Aspect ratio is just the ratio of the width of the tread to the sidewall height. In theory, I think you are thinking the diameter of the tire could change because the angle of the sidewall changes but the difference is so slight the better answer is that it makes no difference. In other words, changing the angle of the sidewall by the the 1/4 inch difference in position Bob calculated does in theory also change the diameter of the mounted tire but that ignores little factors like the sidewall is flexible (we are talking about radials so they are quite flexible) so it isn't really straight lines to start with and the diameter changes with tire wear and air pressure too. Air pressure changes both due to cold air pressure change and operating temperature. So in practice, if there is any difference at all in diameter, it is negligble.
> 
> ...


Jim, my opinion was based only on the fact that this is a staggered rim setup. The rim width is within range for the tire so from the tire manufacturers standpoint the tire will fit with no problem....we agree. BMW had a reason for putting a larger tire on the larger rear rim...they think it changes "something" or they would have used the same size tire front and rear. Although the tire would mount with no issues, I didn't think it was the right decision.

I don't think FastBob gave up, it just wasn't worth our difference of opinion to turn into an argument. I have no desire to fight with anyone. The only thing that upset me was the "WTF" comment. If someone thinks I am wrong that is okay but I don't usually expect to get reactions like that...especially from people I don't know. I enjoy this board, haven't been here long and love my BMW. Everything is good. :thumbup:


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## Slaymaster (Oct 17, 2009)

Bremen Ben said:


> Is it ok to put same size tire on all four rims even if the wheels are staggered set? After much deliberation I now decide to use my 18 inch as winter wheels; it's 245/40-18 front and 275/35-18 rear staggered set. Only problem is, my dealership can't find the Bridgestone Blizzak by now for the 275/35-18 rears.
> 
> As an alternative, the dealership told me the 245/40-18 rubber can also be mounted on the rear wheels even though the rear wheels are wider. Basically I would have 245/40 on all four corners.
> 
> Does anyone have this type of set up? Would there be any problem with mounting narrower tires on wider wheels?


Agreed you shouldn't change the tires back and forth each season for the sake of the bead. Understanding you already made your snow tire purchase I think I would had done things a little different.

I would had purchasd a new set of rims I really liked for the summer tires and then sold the 2 stock rear rims on Ebay or this site. Then puchase 2 new rims the same as the stock front rims. Now you'll have 4 equal size rims for the snows and lesser of a chance of severe curb rash on those rears.

Or just buy a set narrower 17s with rims from Tire Rack as they are better in the snow.

Just my 2 cents. Best of luck and be careful with the rear rims and curbs.


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## JimD1 (Jun 5, 2009)

Fast Bob,

Thanks for the offset definition. Pictures work great for me. So what is different front wheels versus rear? Offset? If I were to buy new wheels, could I buy same size (backspace and offset) for fronts and rears? Could they be interchangable, in other words?

WgMc,

It's my speculation but I think BMW put wider tires on the back because of looks and to provide more traction for launch. With the wider tire, they went with a wider rim. The normal rule of thumb (the definition of this phrase is interesting at least if you are male) I use is that going up or down one size is pretty safe. In other words going from a 245 to a 235 or a 255 shouldn't get the tire outside the fender (illegal in some area) or result in interference with the car when you are turning or be too much weight for the shock or cause any other problem. And if you adjust the aspect ratio you can keep the diameter almost the same and avoid issues with the speedometer/odometer. But the more change you make, the larger the chance of an issue becomes.

I think staggered tires are mainly a "looks cool" thing with a minor performance benefit if you are trying to accelerate really hard. I think same size all around is more practical. And I am more practical than I am a stoplight racer so I would rather BMW just go same size all around.

Jim


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## Bremen Ben (Sep 1, 2008)

Indeed I was originally planning on going with a separate set of 17" tire/wheel snow setup; having hard time giving up the more sporty look of the 18" wheels at the last minute though... Thus end up with the 18" snow shoes.

Oh well I guess I will probably just get a separate set of cheap 18" rims this fall for the snow shoes and leave the staggered rims for summer tires; or tell the Mrs. I "have no choice but to" upgrade the summer setup to 19" all together...:slap:

Here is the side view of the rear:









Compare to the front:









On second look, the gap between the rear rim and tire wall is really not noticeable. I am glad.


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## Bremen Ben (Sep 1, 2008)

WGMc said:


> Ben, if you want to rotate the tires I would not rotate front to rear but rather side to side. I haven't researched your tires and may have missed it but if the tires are not directional you should be able to do that without any tire damage and that would keep the wider rim on the rear. If they are directional then dismount is the only way and that is a lot of trouble. Staggered setups are a pain, I have them on my car.


Unfortunately these are directional..

It seems the consensus is against demounting and remounting tires every season. I will have to rethink how I want to do this come next fall...


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## Fast Bob (Jun 4, 2004)

Bremen Ben said:


> Unfortunately these are directional..
> 
> It seems the consensus is against demounting and remounting tires every season. I will have to rethink how I want to do this come next fall...


There are plenty of wheels available (used), sometimes at really good prices....if you`re patient, you can usually find what you want....it`s to your advantage to have a dedicated set of winter tires mounted and ready to change, makes life a lot simpler.


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## Fast Bob (Jun 4, 2004)

JimD1 said:


> Fast Bob,
> 
> Thanks for the offset definition. Pictures work great for me. So what is different front wheels versus rear? Offset? If I were to buy new wheels, could I buy same size (backspace and offset) for fronts and rears? Could they be interchangable, in other words?
> 
> ...


Yeah, the staggered look is strictly for "show & tell"....it actually detracts from "The Ultimate Driving Experience" because it induces understeer....If you`ve been driving a staggered setup for any length of time, and switch to a "square" setup (same size on all 4), you`ll notice that the car seems more responsive and better-balanced. 
And yes, with a staggered setup, the rear (wider) wheels will have a higher offset number, the purpose is to keep the rim centered in the wheel well, minimizing potential clearance problems.


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## Slaymaster (Oct 17, 2009)

Fast Bob said:


> There are plenty of wheels available (used), sometimes at really good prices....if you`re patient, you can usually find what you want....it`s to your advantage to have a dedicated set of winter tires mounted and ready to change, makes life a lot simpler.


Be careful with used rims. Although there are used rims for sale, some may have been replaced as a result of pothole damage. I have 18s and while I had the run flats, I hit a pothole and bent one. The rim doesn't lose air, but I feel the vibration between 60 and 70.

So needless to say, I need to drive 70+!:thumbup:


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## Bremen Ben (Sep 1, 2008)

Maybe a silly question... For those of you who have a separate snow tire/wheel set, what do you do with TPMS? Do you buy another set of TPMS or do you just go without (don't even know what the car would react without TPMS installed)?


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## QuoteWarz Insurance (Dec 17, 2009)

It is fine the use the same size tires on a staggered wheel set up. It will give the tire a stretched look to it which the Drifters love, but most likely won't look good on a BMW. You can do this and then next winter spring for a different set up.


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## Rickman59 (Oct 30, 2013)

*Rim size?*

Hi there, I have just fitted a staggered 17" set of style 161's on my E36. Instead of the rear 255/40 I went with 225/45 all round. This size keeps the original gearing ratio and works well. I went for the same size all round because 255/40 was just too much for the rear guards to handle. The rims are 8" front and 8.5" rear with appropriate offsets to match. What have I noticed? The rear tyres clear the guards and have a slightly stretched (inwards) look, whilst the front has that nice slightly rounded look. Would you notice if it wasn't pointed out? Hell no. And it drives beautifully. However, I think if the "stagger" was more than 1/2" then it would start to look wrong. Just my POV.


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## jglunariojr (8 mo ago)

Bremen Ben said:


> Is it ok to put same size tire on all four rims even if the wheels are staggered set? After much deliberation I now decide to use my 18 inch as winter wheels; it's 245/40-18 front and 275/35-18 rear staggered set. Only problem is, my dealership can't find the Bridgestone Blizzak by now for the 275/35-18 rears. As an alternative, the dealership told me the 245/40-18 rubber can also be mounted on the rear wheels even though the rear wheels are wider. Basically I would have 245/40 on all four corners. Does anyone have this type of set up? Would there be any problem with mounting narrower tires on wider wheels?


 Yes, I do it in my BMW X5 2011 I upgraded my tires for front 285/40 r20 and the rear tire 285/40 r20 on a staggered Rims. It’s still looking good.


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