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[Boost2M3]

Hello M3 community,

I have a question about which tire sizes to go with.

Some information:

Car: 2011 E92 M3 competition package
Suspension: stock ZCP
Wheel sizes: (Front) 19x9.5 et20
---------------(Rear) 19x11 et25

Tire choice: Michelin PSS or (maybe AD08, but heard it might have rub issues)

Some thorough research on the forum, it seems popular tire sizes would be:
(Front) ----------------- (Rear)
255/35/19 ------------ 275/35/19
255/35/19 ------------ 295/30/19
265/35/19 (too tall?)-- 295/30/19
265/30/19 ------------- 295/30/19
275/30/19 ------------- 295/30/19
----------------------- 305/30/19 (rub?)

The questions: ( I apologize for newbie questions, but I haven't found a definite answer yet)

1.) I'm having a dilemma for the front, should I go with 255/35/19, 265/30/19, or 275/30/19? Would any possibly cause rubbing?

2.) Would the 275/30/19 or 265/30/19 cause the front to have more of a gap between the fender and the wheel than compared to a 255/35/19? I know 35 is a taller profile than 30 but I'm not sure by how much.

3.) How about the rears? Would 295/30/19 cause more of a gap compared to a 275/35/19 or would it be barely noticeable?

4.) Also, why do some run a higher profile in the front and a lower profile in the rear, for example the 255/35/19 (F) and 295/30/19 (R)? Would this make the car uneven?

In my opinion, for the rear I like it wide , so I'm swaying towards 295/30/19 or if possible with no rubbing 305/30/19.

[jra85]

EDIT: Disregard post, did not realize you're not using ZCP wheels.

[kawasaki00]

275/295 is your best option. If you lowe rit in the rear you will probably just rub with the 25 offset though.
Dont go the 255/295 route. I did it and figured out just like I was told the front really starts to push at max grip relative to the rear. The 275 front is a better overall balance to the 295 rear.
This last weekend I could make the front tires squal pretty easy and the rear was rock solid on a mountain run with 255/295. I will be going to the 275 front shortly

[RD1M3]

I'm running 265/30 PSS on 19x9.5 et18 and 295/30 PSS on 19x11 et25 rears on KW Sleeves and have minor rubbing on dips in the rear, no rubbing in the front. You would definitely rub the fender on bumps/dips with 305s on ZCP, and 265/35 are too tall to run in the front, you would rub with those also.
The 275/30 and 295/30 have the closest diameter to that of the stock 245/265 tires, so the fender gap wouldn't change noticeably.
The profile difference front to rear is only due to the width difference in the tires. In order to get a similar size sidewall on a narrower tire, the profile (30 vs 35) has to be higher.

There is a great calculator here that will help:
http://www.e90post.com/forums/forumdisplay.php?f=12

As always, if Slicer would like to weigh in, I'll defer to his expertise with all things tire/wheel related.

[jra85]

Originally Posted by RD1M3

As always, if Slicer would like to weigh in, I'll defer to his expertise with all things tire/wheel related.

Slicer's opinion: 255/35 and 275/35 on ZCP wheels. Done

[kawasaki00]

Originally Posted by JAdamz

Slicer's opinion: 255/35 and 275/35 on ZCP wheels. Done

But the guy is not running zcp wheels.
op says 9.5/11 wheels
275 is too stretched on a 11" wheel

[jra85]

Originally Posted by kawasaki00

But the guy is not running zcp wheels.
op says 9.5/11 wheels
275 is too stretched on a 11" wheel

Ahhh completely missed that! Disregard my first post then, and Slicer should definitely weigh in after all

[s85e90]

I run 285/35 on an 11" wheel (which is in guidelines) and there's 0 stretch and it looks perfect.

[M3/4 life]

255/35/19 front

295/30/19 rear

and you'll be good to go!

[slicer]

Here are my thoughts... since it appears as if there is some expectation that I would have an opinion on this topic.

First of all it appears as if you don't understand how tire sizing works. The profile height is a ratio based on the tire width. A 245/35 tire has almost the exact same sidewall height as a 275/30 tire. (245 * 0.35 = 275 * 0.30)

Rear - 11" wheel - I would definitely run 295's - PSS for street, AD08 for street / track. All of the sizes you listed will fit with the exception of the 305/30/19. I would definitely lean towards a 295/30/19 on an 11" wheel. I currently have 295's on an 11" wheel with the same et25 offset. I have G-Force Rivals and they run super wide - even wider than Yokohama AD08's. I have very slight rubbing on the plastic fender liner where there is a protrusion at the attachment point of the rear bumper and fender. I wouldn't expect to have any issues with Michelin PSS which run round at the tread shoulder. Yokohama AD08's may graze the liner but only in big bumps with the car loaded.

Front - 9.5" wheel - I would definitely run 275/30/19. I would never pair a 255 front with a 295 rear unless you want to add understeer to the car. A 265/30 is a smaller diameter than OEM and it will be the shortest sidewall height of all of the options you listed. It will be easier to fit than a 275/30 but it will have a shorter sidewall height which I don't like. Your front offset is fairly aggressive so I would plan to pull your front alignment pins and max out your OEM camber. You will be able to get around -1.6 which is mild IMO (I run -2 on the street and -2.8 on the track). The car responds well to camber in the front and you won't have significant inner tire wear unless you add too much toe. Toe is harder on tires than camber. Without camber the 275's will look a little funny, stick out past the fenders, and possibly rub. Lastly the 275's will graze the back of the fender liner at full lock (so will 255/35's) which is not a big deal and you won't even notice it unless you inspect your fender liner. 275's in the front is all that I run on this car and all that I will ever run because I love the extra grip.

[slicer]

Originally Posted by s85e90

I run 285/35 on an 11" wheel (which is in guidelines) and there's 0 stretch and it looks perfect.

I have run 285/35/18 Michelin PSS on an 11" wheel. I don't know what your definition of stretch is but I found them to be as stretched as I would ever want. What I'm trying to say is that they looked stretched to me... Not over stretched but definitely stretched. Here's a pic. I was able to run 11" et18 because of the stretch of the 285/35 (see pic below). I'm now running 295/35 with 11" et25 and there is zero room to go more aggressive.

[s85e90]

Originally Posted by slicer

I have run 285/35/18 Michelin PSS on an 11" wheel. I don't know what your definition of stretch is but I found them to be as stretched as I would ever want. What I'm trying to say is that they looked stretched to me... Not over stretched but definitely stretched. Here's a pic. I was able to run 11" et18 because of the stretch of the 285/35 (see pic below). I'm now running 295/35 with 11" et25 and there is zero room to go more aggressive.

Depends on tire also, but a Nitto in 285/35 is not stretched on an 11". the 275 is, but the 285 is just right and totally flat. The rubber on mine still covers the lip of the wheel. I also run an 11" rear et 18 so this is as big as I can go with as low as the car is.

[Boost2M3]

Thanks everybody for the informative responses! Also slicer solid post, you nailed most of my questions! So it is looking like 275/30 fronts and 295/30 rear for me.

[kawasaki00]

Originally Posted by kawasaki00

Dont go the 255/295 route. I did it and figured out just like I was told the front really starts to push at max grip relative to the rear. The 275 front is a better overall balance to the 295 rear.

Originally Posted by slicer

Front - 9.5" wheel - I would definitely run 275/30/19. I would never pair a 255 front with a 295 rear unless you want to add understeer to the car. A 265/30 is a smaller diameter than OEM and it will be the shortest sidewall height of all of the options you listed. It will be easier to fit than a 275/30 but it will have a shorter sidewall height which I don't like. Your front offset is fairly aggressive so I would plan to pull your front alignment pins and max out your OEM camber. You will be able to get around -1.6 which is mild IMO (I run -2 on the street and -2.8 on the track). The car responds well to camber in the front and you won't have significant inner tire wear unless you add too much toe. Toe is harder on tires than camber. Without camber the 275's will look a little funny, stick out past the fenders, and possibly rub. Lastly the 275's will graze the back of the fender liner at full lock (so will 255/35's) which is not a big deal and you won't even notice it unless you inspect your fender liner. 275's in the front is all that I run on this car and all that I will ever run because I love the extra grip.

Slicer is the one that told me not to run the 255 with the 295, the first time I really drove the car to its limit it pushed pretty good. I only have 9" front so that is why I did it anyway.
I am ordering a set of 10" fronts so I can go to the 275. Like slicer said I run -1.7 on the street.

[s85e90]

I run a 245/285 combo.. Big tire in the rear is nice and you don't have to worry about the car pushing as that's easily rectified w/ an alignment.

[Boost2M3]

Hey slicer, I have edc on my car, is their any precautions I should take while performing the removal of the alignment pins?