Page 1 of 4 1234 LastLast
Results 1 to 25 of 84

Thread: Max width of tires on a Non M Z3?

  1. #1
    Join Date
    Jul 2010
    Location
    Summit IL
    Posts
    1,180
    My Cars
    1997 BMW Z3 2.8L

    Max width of tires on a Non M Z3?

    Ive got a 2.8L 97 Z3 and Im trying to put 18 inch 8.5 and 9.5 on. Will it work?

  2. #2
    Join Date
    Dec 2006
    Location
    OC, CA
    Posts
    9,205
    My Cars
    ML320-GTI-996TT-Bikes
    Those are the sizes I run. Offset 40 all around, no spacers. The front sticks out just a tiny bit. The rear can probably take even more than 9.5.

    Those are rim sizes obviously. I don't think I could get away with wider than 225 tires in the front without rubbing. I have 255 in the rear but could fit much wider if I wanted to.
    Last edited by luciano136; 10-03-2012 at 01:32 PM.

    SOLD MAY '14
    Mods
    : 6psi Supercharger kit; Rogue RSM's; DINAN strut brace; Magnaflow exhaust; Stewart waterpump; Stoneguards, Glove box fix, M Shift knob; Aux input adapter;
    Mesh bumper grill; Projector Z II headlights (35W Xenon), IE alu radiator, ARD wheel studs, H&R coilovers, Work VS-XX wheels/Hankook V12 tires, VANOS fix

  3. #3
    Join Date
    Jul 2010
    Location
    Summit IL
    Posts
    1,180
    My Cars
    1997 BMW Z3 2.8L
    Anything bigger than 9.5 would look like a drag car on our Z's no?

  4. #4
    Join Date
    Dec 2006
    Location
    OC, CA
    Posts
    9,205
    My Cars
    ML320-GTI-996TT-Bikes
    Quote Originally Posted by Nighthawk399
    Anything bigger than 9.5 would look like a drag car on our Z's no?
    Not necessarily as long as the tire profile remains low enough.

    SOLD MAY '14
    Mods
    : 6psi Supercharger kit; Rogue RSM's; DINAN strut brace; Magnaflow exhaust; Stewart waterpump; Stoneguards, Glove box fix, M Shift knob; Aux input adapter;
    Mesh bumper grill; Projector Z II headlights (35W Xenon), IE alu radiator, ARD wheel studs, H&R coilovers, Work VS-XX wheels/Hankook V12 tires, VANOS fix

  5. #5
    Join Date
    Jul 2010
    Location
    Summit IL
    Posts
    1,180
    My Cars
    1997 BMW Z3 2.8L
    Did the 18's help cover the gap between stock suspension and 17''?

  6. #6
    Join Date
    Jun 2011
    Location
    Newport News, VA.
    Posts
    214
    My Cars
    01 Z3 Coupe 3.0i, Z4 2.5
    The Z3 non-///M and ///M cars share the same fenders (except the rear 1.9 models) and will be able to use the same size width tires but the rear rim offsets will be very different (fronts should be same). Keep in mind, when running wheel/tire sizes out to the very very max, fitmit will depend on a lot of things such as suspension system, car alignment specs, and variations of production tolerances from car to car etc.

    So the max sizes I've seen are 255 in the fronts and 315 in the rears without fender mods on ///M models. No reason those will not fit on a non-///M.

    Personally I am currently running (2001 Z3 Coupe 3.0i) a 235/40-18 wrapped around a 18X8 ET40 front with no issues at all and I am lowered approx 1~1.5" on coilovers. For the rear I've got 265/35-18 wrapped around 18X9 ET45 and there is PLENTY of room both inside clearance from the inner fender well and trailing arm and probably a good 3/4" clearance from the outside of the tire to fender lip. I was running the same set up with 225/40-18 front and 255/35-18 rear and found the upsize that I currently am running to ride A LOT better. I can't do a direct compare because I switched tire brands and models, but man what a difference the tiny upsize in tire height made in the ride quality. Later this or next week I will be running the same size tires, but moving to 18X8.5 ET45 front and 18X10 ET43 rear. Camber settings are 1.5* front and 2* rear (adjustable rear subframe maxed for minimum negative camber).

    After I get my supercharger and these tires wear out I might switch to 245/35-18 fronts and 285/30-18 rear.

    The problem I have found in maxing out a non-///M car is getting wide wheels in the correct offset. Everything seems to be geared for the ///M models which run much lower rear offsets. If you want to run a 265/35-18 then a 18x9.5 is a good size and can be bought all day, but if you want to run larger then 9.5 it becomes an expensive pain to find wheels that fit.

    ~Mike....
    Last edited by RacerXTreme7; 10-03-2012 at 02:22 PM.

  7. #7
    Join Date
    Jun 2011
    Location
    Newport News, VA.
    Posts
    214
    My Cars
    01 Z3 Coupe 3.0i, Z4 2.5

    Tires

    Here is my car with the aforementioned 18X8 ET40 fronts and 18X9 ET45 rears. This is with the previous 225/40-18 fronts and 255/35-18 rears. The 235/40-18 and 265/35-18 actually look much meatier and make the car look lower because the tire to fender gap is tighter (and ride better).

    Next week the move to 18X8.5 and 18X10! (same style wheels, just wider).

    ~Mike....
    Attached Images Attached Images
    • File Type: jpg Z3.jpg (125.4 KB, 384 views)

  8. #8
    Join Date
    Dec 2006
    Location
    OC, CA
    Posts
    9,205
    My Cars
    ML320-GTI-996TT-Bikes
    Quote Originally Posted by Nighthawk399
    Did the 18's help cover the gap between stock suspension and 17''?
    It actually made it worse in my case since I kept a similar overall diameter (meaning a lower profile tire). The only way to really fix that large gap is lowering.

    SOLD MAY '14
    Mods
    : 6psi Supercharger kit; Rogue RSM's; DINAN strut brace; Magnaflow exhaust; Stewart waterpump; Stoneguards, Glove box fix, M Shift knob; Aux input adapter;
    Mesh bumper grill; Projector Z II headlights (35W Xenon), IE alu radiator, ARD wheel studs, H&R coilovers, Work VS-XX wheels/Hankook V12 tires, VANOS fix

  9. #9
    Join Date
    Jul 2009
    Location
    Little Rock, AR
    Posts
    2,651
    My Cars
    98 Roadster 2.8L
    Quote Originally Posted by luciano136

    It actually made it worse in my case since I kept a similar overall diameter (meaning a lower profile tire). The only way to really fix that large gap is lowering.
    +1 16/17/18/19 inch rims don't change the gap between the tire and the wheel well.... the external tire diameter remains relatively the same.... just different sidewall heights... so as not to mess with the speedometer / odometer. Suspension lowering is the only way to close the gap.

  10. #10
    Join Date
    May 2007
    Location
    Far Hills,NJ
    Posts
    2,238
    My Cars
    '00 Z3 2.3 Roady, '08 M5
    I've had the same setup in my car. 18x8.5 et30 up front and 18x9.5 et30 out back. I've had 255 and 265 out back with no rubbing. I think 18x10 et25 is doable with 255's as well. I think someone here with a non M coupe has that setup, just can't think of his name.

  11. #11
    Join Date
    Feb 2005
    Location
    Bloomington, Illinois
    Posts
    6,189
    My Cars
    2011 E92 M3, 2007 335i
    I've got 255x17 all around. Up front that is maxed out but I'm sure you can fit 275's out back.
    Now in E92 M3 ZCP -- Absolute beast

  12. #12
    Join Date
    Sep 2012
    Location
    Indialantic
    Posts
    59
    My Cars
    2000 BMW Z3
    225 tires in the front without rubbing. I had 265 in the rear on 18x10, Ive today moved to 19x8.5 fronts and 19x9.5 in the rear, had to swap cause the 18 rear rim offset was way off, make sure your 35-40 offsets with a 18x8 up front, my 19x8.5 offset 35 needed a 5mm spacer, and no larger then 225, or youll run into the strut tower, I have a 235 rubbed out from last week up front.


  13. #13
    Join Date
    Mar 2007
    Location
    Ellay, CA
    Posts
    1,293
    My Cars
    BMW Z3 3.0 VF SC'd
    I've got 275/30's on my 19x9.5's on the back of the coupe...no rubbing. The 10" wide rims will definitely fit on the back of the Z's. In fact, I think a 275 on a 10" rim would be ideal IMO.

    ...on the front, I'm running 235/35's on 19's. I'm gonna go back to 18's on the front, cuz I think it looks better....plus it doesn't push the front as much or as early with the slightly taller sidewalls.

    "You don't win silver....you lose gold."

  14. #14
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    Bumping this thread up...I really like the look of Apex Arc 8's. Would their 17x9 et30 or 17x8.5 et20 wheels work in the rear of a Z3 3.0 coupe? Looking at post 10 in this thread, it sounds like the et30 wheel should work, but I'm less sure about the et20.

    And is it possible to run a concave wheel up front? Again, post 10 makes it sound like an 8.5" wide et30 wheel can work...is that just about as far as you can push it, or would the 8.5 et20 be possible? As I understand it, the front wheel well on the M and non-M are the same, and according to post #22 here, a 17x9 et30 wheel should work up front.

    I know that tire width and ride height play a role in all of this as well, but I was curious if the wheel offsets were at least in the ballpark of what might work.

    Basically, I would like to recreate this look :

    Attached Images Attached Images
    Last edited by kornfeld; 01-21-2015 at 10:16 AM.

  15. #15
    Join Date
    Aug 2010
    Location
    Columbia, Worst Carolina
    Posts
    2,971
    My Cars
    2000 M-Coupe, 1994 SE-R
    The ARC-8 17x9 ET30 should fit well in the rear without issues. That wheel also fits up front, but pokes just a tiny bit and will rub a little (until it self-clearances) with 245 wide tires. You could put a 235 up front and 255 or so in the rear on the same wheels and be pretty well set.

    The 17x8.5 ET20 ARC-8 is a weird wheel for us, in that it is too narrow for most of us to want to run in the rear, and it doesn't fit up front any better than their 17x9 wheel so it makes more sense for most to do the 17x9 all around.

    Your personal goals and concerns will play into this though, so elaborate if you wish.
    Last edited by BenFenner; 01-21-2015 at 10:14 AM.

  16. #16
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    Great, thanks for the info. Two questions:

    -When you say the 8.5" et20 doesn't fit any better up front than the 9" et30, are you saying it will rub a bit as well but be ok, or will it end up rubbing quite a bit more due to the offset difference?

    -Is it a pain in the butt to rotate tires with different widths front and rear? Or do people just run non-directional tires and swap them side to side? This obviously isn't a huge deal, but worth taking into consideration.

    I'm used to running tires on 6.5" or 7" wide wheels, so all of these are going to be a big jump up for me.

  17. #17
    Join Date
    Aug 2010
    Location
    Columbia, Worst Carolina
    Posts
    2,971
    My Cars
    2000 M-Coupe, 1994 SE-R
    The 8.5" wheel is narrower than the 9.0" wheel by 12.7mm, which means if centered on the 8.5" wheel the 9.0" wheel will stick out on each side by 6.35mm. The 8.5" wheel has an offset that is 10mm different, which places it 10mm more outboard than the 9.0" wheel. This means the 8.5" wheel sticks outboard 3.65mm (10mm - 6.35mm) more than the 9.0" wheel, which is where the rubbing happens. So this 8.5" wheel pokes a little more than the 9.0" wheel and it also "stretches" the tire less than the 9.0" wheel which means the tire will take more of a rectangular shape when viewed tread-on which makes the clearance issue worse. The 9.0" wheel is the better option for fitment in all aspects if you stick with their concave ARC-8 wheel. I hope that makes sense.
    If you are okay with going to a flat-faced wheel, there are obviously better options.

    Rotating staggered tires is slightly less effective because you aren't swapping front-to-back, only side-to-side. And this can get even less effective if you have a lot of negative camber (over 2.5 degrees or so) which is common out back on lowered cars. This means to properly rotate, you need to take the tires off of the wheels in the back and mount them on the opposite wheel. This can cause trouble if you have tires with asymmetric tread patterns with an "outside" and an "inside" tread design.
    I have dealt with the worst case scenario, and it's really not that big of a deal, but it does cost some money for tire removal and remounting, and it does limit your choices for performance rubber on the sides where you have a lot of camber (in the rear on my car).
    Last edited by BenFenner; 01-21-2015 at 12:07 PM.

  18. #18
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    Quote Originally Posted by BenFenner View Post
    <snip> I hope that makes sense.
    100%. Thanks.

    Is there any concern with using the same size tires on all four corners? I think I've seen this referenced on the forum as being "square" but I might be misinterpreting that. I ask because I've seen mention of people pairing a relatively large rear tire with a relatively small front tire, and inducing understeer as a result. I would hate to go completely even on all four corners and then end up with something that tends excessively toward oversteer. I was thinking I could go with the 17x9 et30 wheel and 245s all around, which would also solve the tire rotation concern.*

    I forgot to ask: when you say the front tire will self-clearance on these cars, does the fender lip end up getting folded a bit, or does the tire itself get a groove worn into it, or a combo of both? I guess a 235 tire would at least partially alleviate this concern.


    Edit: Found a lot of good info here: http://www.bimmerforums.com/forum/sh...2014-Group-Buy!
    Last edited by kornfeld; 01-21-2015 at 01:43 PM.

  19. #19
    Join Date
    Aug 2010
    Location
    Columbia, Worst Carolina
    Posts
    2,971
    My Cars
    2000 M-Coupe, 1994 SE-R
    There are tons of ways the word "square" is used when referencing tires, and wheels, and wheel/tire combinations so I'm not surprised you have questions. Running the same size tire all around is commonly called a "square" tire setup and is the alternative to a "staggered" tire setup. The same goes for wheels... You can run a square set of wheels versus a staggered set regardless of tire sizes. It just means they are the same size in all dimensions. Then there is the concept of the tire being "square" on the wheel, which I won't get into right now...

    There is no concern with using the same size tires on all four corners, just different behavior of the car that you should be aware of. The stock setup has some understeer built into it using many methods. One of the main methods used to accomplish this on these cars is with a wider tire in the back. If you go to a square tire setup, you can and will lose some understeer which is usually considered a good thing among enthusiasts who are aware of the trade-offs and looking to get more grip and control. It can be less safe in the hands of a driver who is not prepared for it, but we don't get many of those folks around here.

    The people around here who have a large difference in tire width front-to-back are commonly going the other way and inducing a lot of understeer as you've mentioned. This is ususally not what is desired, but they are going for the look of wide wheels and tires as best they can, and the rears of these cars just allow for so much wider rubber than the fronts so the unbalance happens. There are tricks you can do to avoid some of the understeer, but most don't go that far.

    Your concern about excessive oversteer with a square setup is an honest concern, but you can be rest assured that plenty of people go this route and all report how neutral the car is without ever mentioning any sort of excessive oversteer. The difference shouldn't be that dramatic. Our cars being very near 50/50 weight distribution make a square tire setup a good baseline for neutral handling.

    Your idea for 17x9 all around and 245 all around is a good idea. It solves the tire rotation problem and your only issue as far as I see will be in the front. There is a plastic fender liner that has a crease in it where the hood recesses into. This crease tends to wear through (no damage to the tire) on moderately lowered cars with moderate spring rates. It can also be "repaired" with black electrical tape or a small bead of black silicone. I plan to do that for mine some day.

    It's also possible that some camber up front could also avoid this issue. I don't know if my front strut hats are swapped or not, so I can't say for sure, but I think swapping the hats to get a little camber might also let this setup fit with absolutely no rubbing. I have the setup you're aiming for on the front of my car, and I'm speaking from my experience.
    Last edited by BenFenner; 01-21-2015 at 03:33 PM.

  20. #20
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    Last edited by kornfeld; 01-22-2015 at 07:24 PM.

  21. #21
    Join Date
    Feb 2005
    Location
    Bloomington, Illinois
    Posts
    6,189
    My Cars
    2011 E92 M3, 2007 335i
    On a non-M, you can fit 255's on a 17x9 et30 up front but will need a little camber to clear into the top of the hood/fender well. You could easily fit 275's on the rears without too much issue and a little spacing.
    Now in E92 M3 ZCP -- Absolute beast

  22. #22
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    In your experience, have you found that 245 width tires on a 17x9 et30 wheel have the potential to clear up front without going too aggressive on camber?

  23. #23
    Join Date
    Mar 2007
    Location
    Ellay, CA
    Posts
    1,293
    My Cars
    BMW Z3 3.0 VF SC'd
    My current set-up:

    APEX EC-7's

    Fronts: 9x18 ET 31 w/ Hankook Ventus V12 K110 in 245/35/18
    Rears: 10.5x18 ET 27 w/ Hankook Ventus V12 K110 in 285/30/18

    I'm rolled in the back, and everything fits like a glove all around.


    Use these tools to help you:

    http://tire-size-conversion.com/tire-size-calculator/

    http://www.willtheyfit.com/
    Last edited by danomite; 01-26-2015 at 11:06 PM.

    "You don't win silver....you lose gold."

  24. #24
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    Cool, good info to have. What suspension are you running, and can you estimate how much lower you are than stock ride height?

  25. #25
    Join Date
    Dec 2014
    Location
    San Francisco, CA
    Posts
    1,138
    My Cars
    2001 Z3 3.0 Coupe
    I spoke with a rep at Apex just to get their input on things. He sounded iffy about the 17x9 et30 fitting at all. Is that just them being conservative, given that they actually sell the wheels and probably don't want to have anyone stuck with the tires rubbing at all?

Page 1 of 4 1234 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •