# Wheel and Tire Size Recommendation? Will it fit?



## spencer500 (Oct 21, 2012)

I am seeking some advice on wheel / tire choices. I currently have a 2011 335d which came with 17" wheels. I upgraded them to 18" wheels last year. I put Rial (low pressure cast) wheels. After a year of driving on Pennsylvania roads, I noticed today that all of them have slight bends in them. Not terrible, but enough that on a smooth road (hard to find), I can feel them.

So here is my questions.

1. If I purchased a better quality wheel (1pc. Low Pressure Cast w/Flow Forming) such as a BBS CH-R wheel, is there a chance that I would have less of a chance of bending a wheel? I understand that massive potholes will bend any wheel, but that is not my case. 

2. If I stay with 18" wheels, does anyone know if a 235/45-18 tire would fit on my 335d? (I currently have 225/40-18). I am thinking that the 45 profile tire might give me a bit more sidewall. Am I wrong? Can anyone recommend an ideal tire size?

3. Or, should I just go back to the 17" wheel? How much performance will I sacrifice? If I do go back to 17" wheels, can I run 245/40-17 or what size would anyone recommend?

I thank anyone in advance who will take time to reply back to me to help me with these questions?


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## Hoooper (Jun 17, 2013)

Yes if you get better wheels they will last longer under the same conditions.

Tire sizes that fit depend on the wheel offset and whether you are base/sport/lowered. I'm running 235/40 18 front and 275/35 18 rear with sport suspension, no rubbing or anything like that


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## robster10 (Oct 8, 2012)

I went with original BMW 18" that I found used. Many 335's out there with clean staggered set ups that many people get rid of. Although the aftermarket wheels are lighter they are also weaker.


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## Hoooper (Jun 17, 2013)

I don't know what you mean about weaker aftermarket wheels, I guess the really cheap ones could be weaker but the stock wheels are pretty darn brittle. The stock wheels are cast which is the cheapest and generally least reliable method they could use. Any wheels that are properly designed, aren't massively lighter than stock, and are made by flow forming, forging, rotary forging, etc will be stronger than stock. I cracked the crap out of two stock wheels in 6 months which is why I abandoned them. Lot of good run flats do you on a cracked wheel.


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## spencer500 (Oct 21, 2012)

Hoooper said:


> Yes if you get better wheels they will last longer under the same conditions.
> 
> Tire sizes that fit depend on the wheel offset and whether you are base/sport/lowered. I'm running 235/40 18 front and 275/35 18 rear with sport suspension, no rubbing or anything like that


Thanks for the reply. My 335d is the "Base" model with no suspensions modification yet. I am looking for a square setup, so it sounds like the 235/40-18 would be a slightly better option than my 225/40 and will give me a slightly taller sidewall. I am glad to know that size will fit.


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## Flyingman (Sep 13, 2009)

I have a similar set up as Hooper. I went with 235 up front and 255 or 265 in rear. Just wanted to get a bit more tread down as my fronts were wearing a bit fast.

It seems to have helped reduce wear but my MPG dropped a bit.

I also wanted a bit more rubber along the edges to help with curb rash when parking.


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## luigi524td (Apr 4, 2005)

I suggest you investigate the tire size alternatives for 17 and 18 inch rims on tirerack.com ... I'll always go with "stock" sizes since those are most likely to have sufficient clearances in all directions. However, in my experience moving up to a slightly taller sidewall (e.g. aspect ratio from a 40 to a 45) all-around on a 'square' set-up is usually OK it's still best to confirm that all clearances are OK. As far as resistance to bending/breaking etc I haven't had a recent BMW with 17's but based on the move from my '07 530xi (245/40x18) to my '13 535xDrive (245/45x18) and traveling the same rotten roads I am LUCKY so far (had 2 bends/bent rims on the '07 - "0" on the '13) ... NOW I'M KEEPING MY FINGERS CROSSED!!!!!! ... Don't know if it's the better RFTs on my newer BMW or the extra 5mm?? As for 17's - I know PA roads are as bad as NJ roads ... If tank treads were an option they'd be my first choice!! I've read that the handling differences under NORMAL conditions were minimal for the _AVERAGE BMW DRIVER_ - If yours is autocrossed or rallied on the PA Turnpike that general statement may not apply ;-)

Last point - remember that your car's speedometer and odometer will be affected whenever the rolling diameter of the tire (from stock) changes ... keep that in mind on the road or for manually calculating mileage and fuel economy.


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## 335dwanted (Aug 1, 2014)

235/45 would be around 5% larger diameter; in my opinion this is much too large an increase even if they fit, you are materially effecting your gear ratios at that point and will likely degrade acceleration.

The other forum has a nice tire size calculator that will compare different sizes for you.

Your best bet is going back to 17s w/ the higher aspect ratio. If you go to 235/40 on 18s that will give you a little bit larger sidewall. I would also suggest paying attention to the difference between the front and rear diameters; at some point the difference may have a negative effect on the traction control but I cannot say with any certainty if that is true, perhaps others can provide input based on experience with that.



spencer500 said:


> 2. If I stay with 18" wheels, does anyone know if a 235/45-18 tire would fit on my 335d? (I currently have 225/40-18). I am thinking that the 45 profile tire might give me a bit more sidewall. Am I wrong? Can anyone recommend an ideal tire size?
> 
> 3. Or, should I just go back to the 17" wheel? How much performance will I sacrifice? If I do go back to 17" wheels, can I run 245/40-17 or what size would anyone recommend?
> 
> I thank anyone in advance who will take time to reply back to me to help me with these questions?


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## Flyingman (Sep 13, 2009)

Flyingman said:


> I have a similar set up as Hooper. I went with 235 up front and 255 or 265 in rear. Just wanted to get a bit more tread down as my fronts were wearing a bit fast.
> 
> It seems to have helped reduce wear but my MPG dropped a bit.
> 
> I also wanted a bit more rubber along the edges to help with curb rash when parking.


To be clear I stayed with original 18" ratios, 235/40R18 Front and 255/35R18 Rears.

I like the feel, and I no longer see the quicker wear on the front outsides like I did originally.

But I did note a slight knock on my MPG, perhaps 1-2mpg is my best guess.

If I lived with really poor roads I'd go with 17s to get more sidewall. Low aspect ratio tires really take a beating.


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## ChasR (Aug 29, 2012)

I bought the ARC-8 wheels from Turner Motorsports. I was able to fit 255/35-18 on the front, using a 3mm spacer. 265/35-18 fit on the rear without scraping if you run at least 2 degrees negative camber. The 255s in the front affect fuel economy negatively.


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## robster10 (Oct 8, 2012)

Hoooper said:


> I don't know what you mean about weaker aftermarket wheels, I guess the really cheap ones could be weaker but the stock wheels are pretty darn brittle. The stock wheels are cast which is the cheapest and generally least reliable method they could use. Any wheels that are properly designed, aren't massively lighter than stock, and are made by flow forming, forging, rotary forging, etc will be stronger than stock. I cracked the crap out of two stock wheels in 6 months which is why I abandoned them. Lot of good run flats do you on a cracked wheel.


Sorry Hoooper: I meant to say the cheaper knock offs out there. There is good quality aftermarket but I believe they're in a different price point. I find most of these on the local adds up here where they are being sold off but state 1-2 of 4 have a crack. I also changed over to non-RFT and feel the ride has smoothed out considerably.


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## Hoooper (Jun 17, 2013)

robster10 said:


> Sorry Hoooper: I meant to say the cheaper knock offs out there. There is good quality aftermarket but I believe they're in a different price point. I find most of these on the local adds up here where they are being sold off but state 1-2 of 4 have a crack. I also changed over to non-RFT and feel the ride has smoothed out considerably.


Yeah I agree, wheels are one of those items where there is a pretty distinct line between low and high end, and the price comparison is just as distinct. You definitely have to pay to play when it comes to wheels, but if you do pay up for the better wheels you will likely end up a lot happier in the long run.


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## spencer500 (Oct 21, 2012)

Thank you all for your reply. Can anyone give me advice on the Beyern Spartan wheel? It looks like it is a rotary forged wheel and should be strong. Anyone have any feedback on these wheels?


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## Hoooper (Jun 17, 2013)

Never heard of that wheel manufacturer. If they have good reviews and you can confirm they are rotary forged I would say go for it. Definitely spend time looking into their reputation if you don't already know if they're good


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## Flyingman (Sep 13, 2009)

http://www.beyernwheels.com/BMW_wheels_beyern_spartan.php

Looks good. Using the Bavarian Flag logo which appears similar to the BMW Logo, but then we all know what the BMW Logo really is!:thumbup:


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## Flyingman (Sep 13, 2009)

Flyingman said:


> To be clear I stayed with original 18" ratios, 235/40R18 Front and 255/35R18 Rears.
> 
> I like the feel, and I no longer see the quicker wear on the front outsides like I did originally.
> 
> ...


Folks, just a follow up. My rear Michelin PSS (265) are now down to the bar after 35k miles. The fronts (235) still have quite a bit of tread, maybe another 5k or so, but I will change out the complete set with the same tires. Going wider up front appears to have extended their lifetime.

These Michelin PSS are really fantastic tires, great grip, long wear, good handling, never an issue under any circumstances.

These will be my 3rd set of PSS and my 4th set of tires on this car. Averaging about 35k per set other than the OEM RFTs which sucked.


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## GreekboyD (Jan 25, 2012)

Flyingman said:


> Folks, just a follow up. My rear Michelin PSS (265) are now down to the bar after 35k miles. The fronts (235) still have quite a bit of tread, maybe another 5k or so, but I will change out the complete set with the same tires. Going wider up front appears to have extended their lifetime.
> 
> These Michelin PSS are really fantastic tires, great grip, long wear, good handling, never an issue under any circumstances.
> 
> These will be my 3rd set of PSS and my 4th set of tires on this car. Averaging about 35k per set other than the OEM RFTs which sucked.


I ran 235x40x18 and 265x35x18. Last week I got new MPSS and kept same size in rears but went 245x35x18 up front:

Link


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## Hoooper (Jun 17, 2013)

Wow, I got about 25k out of my rear 275/35 PSS, but on the plus side I got about 55k out of the front 235/40 PSS.


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## Flyingman (Sep 13, 2009)

Hoooper said:


> Wow, I got about 25k out of my rear 275/35 PSS, but on the plus side I got about 55k out of the front 235/40 PSS.


I was finding my fronts were wearing quicker than the rears until I increased tire width up front to 235. Our cars are rear wheel drive so the rears should go faster.

You cant go front to back but you can do left to right on the PSS, which may buy you a few more k miles.

35k on performance summer tires is pretty darn good IMHO.:thumbup:


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## Flyingman (Sep 13, 2009)

Just replaced my PSS this weekend, about 35k miles. Rears were almost slicks, fronts could have gone a bit more. I wouldn't waste my time with replacing just the rears though.

I think the combination of down shifting (avoid braking too much) with the 235 up front has extended the life of the front tires.

This will be my third set of the PSSs and I cant say anything bad about them at all. They are great tires.

Wish I could find something similar for the GL350.


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