12-30-2015, 02:37 PM | #1 |
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X5M/X6M Wheels and Tires Combo Myths - Q&A HERE
Hello friends. Just a background, I'm a nerd when it comes to wheels and tires. Jason and itzkoolkidkam would know, check their sick setup out.
Anyways, I would like to debunked some of myths out there on wheels and tires combo. What can you use and what can't you use. Post your questions here and I'll help you. I'll start. The first common question as follow: Q: The X5M uses 285/40/20 (or 285/35/21) front and 325/35/20 (or 325/30/21) rear, does running narrower or wider combos throw an error code? A: Not really. OEM X5M 285/40/20 (or 285/35/21) front and 325/35/20 (or 315/30/21) have overall height of 736mm front and rear. This means there is 0% delta between front and rear rotational diameter. As long as your new setup has a 0% rotational delta between front and rear, it will not be an issue. Example A, 275/40/20 F and 315/35/20 R both have a total tire height of 728mm. This means when paired together for front/rear, there is a 0% delta on rotational diameter front and rear. Your car ECU will not sense any issue with this setup. Example B, 285/40/20 all around have a total tire height of 736mm. This means there is a 0% delta on rotational diameter front and rear. Your car ECU will not sense any issue with this setup either. Example C, 275/40/20 F and 325/35/20 R, the front is 728 mm tall and rear is 736mm tall. This means when paired together for front/rear, there is a 1.2% delta on rotational diameter front and rear. Your car ECU will think your front wheels are slipping as they're spinning 1.2% faster than the rear, creating an issue. Example D, 285/40/20 F and 315/35/20 R, the front is 736mm tall and rear is 728mm tall. This means when paired together for front/rear, there is a 1.2% delta on rotational diameter front and rear. Your car ECU will think your rear wheels are slipping as they are spinning 1.2% faster than the front, creating an issue. Conclusion: Running different wheel/tire sizes than stock doesn't throw a code with the ECU, as long as the front and rear setup rotational diameter DELTA are similar to stock. In this case, most AWD vehicles like the X5M, likes a 0% rotational diameter delta between front and rear. As long as your tire combos achieve close to 0% delta between front and rear, you can run it on your car. Some cars like the F80/F82/F83, prefers the rear to be 2.6% taller. In that case, the new setup rear tires must be close to 2.6% taller in the rear to reduce computer intervention. I hope this is helpful, please post more questions. I'd love to hear them. Cheers, Jimmy
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Last edited by JNoSol; 12-30-2015 at 10:50 PM.. |
12-30-2015, 02:51 PM | #2 | |
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12-30-2015, 03:10 PM | #3 |
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that's no problem since the width doesn't effect the rotational diameter. HTH.
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12-30-2015, 03:16 PM | #4 | |
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I am finding there are few options for the new 285 front and 325 rear 20" set up on the F86. Almost no options/availability for snow/winter tires even running 285 front and rear, but plenty of choices for 275 315 combo. The 10 mm difference in width is less than 1/2 inch. I've been told that it is done all the time and there is no issue mounting tires slightly narrower than the rims. Is that true? Thank you. |
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12-30-2015, 03:38 PM | #5 | |
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12-30-2015, 03:41 PM | #6 | |
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The wheels are within the tire specs, so no issues. You're referring to running 1 tire width smaller on our OEM wheels (20x10.5 and 20x11.5), which is common. It's only .5" inch difference compared to my setup, you won't be able to notice the difference (mine will just look a bit meatier compared to your proposed setup). No performance difference or ECU issues. Go for it. Tip: Search for 2012 or 2015 X5 non-M tires with staggered 20s. It's the right size you're looking for. Just run Contis DWS06 if you don't need true winter tires. It's the best all seasons for cold weather/snow/ice. Combined with the X5 platform, it rolls around like a tank.
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12-30-2015, 03:45 PM | #7 |
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Isn't the OEM 21" rears 325 too? You typed 315/30/21.
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12-30-2015, 03:47 PM | #8 |
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LOL, good catch on the typo. Yes, I should know as I have 21s.
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12-30-2015, 03:49 PM | #9 | |
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12-30-2015, 03:50 PM | #10 |
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You're welcome. Wish you a prosperous and healthy New Year.
Damn, you live in NYC. You can charge people a $1k to park at your house on NYE. Even Applebees Time Square are charging people $1,500 to eat there.
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12-30-2015, 03:53 PM | #11 |
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I'm not in Manhattan, I'm in one of the outer boroughs. Close enough yet far enough.
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12-30-2015, 04:01 PM | #12 |
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Gotcha. I traveled to NY almost every week for 9yrs, that was enough excitement for me.
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12-30-2015, 05:13 PM | #13 |
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Hey, I have a set of HRE's that were on my E70 X5M that I want to put on my F85 in the spring. Would you happen to know if the front and rear offsets are the same in the F85 and the E70? I know I have to have the rear Hub diameter bored out to 74.1 but no one seems to know if the offsets would work. Thanks!
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12-30-2015, 06:24 PM | #14 |
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Looking for Help for Winter Wheel/Tires for F85
Was hoping to get some of your wizardry regarding wheels and tires.
I just purchased the 2016 X5M F85. I desperately want to get winter tires that I like - the Nokian H2's. I can't find any sizes that work for the car. Any ideas or advice? Just go with the OEM BMW 20's for winter and stick with the Pirelli's? Thanks much! |
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12-30-2015, 10:48 PM | #15 | |
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The good news is, it's always easier to make the holes bigger vs trying to add material to reduce the bore diamter.
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12-30-2015, 11:04 PM | #16 | |
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Cheaper than the Pirellis in 285/325. http://www.tirerack.com/tires/tires....omCompare1=yes http://www.tirerack.com/tires/tires....omCompare1=yes If you don't like it, try the Contis DWS06 (275/40/20 front and 315/35/20 rear). I promise you it's more than enough for an X5. I've been to the Rockies many times with my E70 X5s with Contis DWS, it's more than enough to conquer any condition as long as the driver has good judgement. I've never been stuck or close to being stuck, the car seems to always be in control with DWS. Here's my original review of the Contis DWS: http://www.xbimmers.com/forums/showthread.php?t=760813
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12-31-2015, 10:00 AM | #17 |
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Thanks for the helpful thread. A couple points: folks, when posting tire sizes make sure you post wheel widths as well. It makes establishing if fitting a tire outside of standard spec will work. I'm a scientist, so I'm nitpicky (apologies in advance )...
One question I'd like some input on is the true benefit from running a non-staggered tire setup like the OEM 20" winter setup with 285s front and back, versus a staggered winter setup. I've been told that the better winter wheels are always narrower, as you get a smaller contact patch with more pressure per surface area, and therefore you get better "bite" on snow and ice. I imagine this is true. But it's also sounding like JNoSol you've had great luck running a staggered setup, and on the DWS tires as well, which aren't pure winter tires (like the Pirelli Scorpions that come with the OEM 20 winter setup). So I'm guessing that it's not an issue, and that a staggered winter setup, and even one without a true full-bore winter tire is fine for the majority of us who aren't living in the great white north. I guess I'm a little bummed I'm now going to be waiting for a 4k set of OEM 20s for winter through mid Jan at last estimate when I could've gotten a nice custom set in quicker time... |
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12-31-2015, 10:08 AM | #18 |
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I wanted to attach a couple links I found helpful too, courtesy of tire rack. 1 on tire/wheel info in general, and another that allows you to compare old and new potential wheel/tire combos (and compare delta in rotational diameter, etc.). HTH
http://www.tirerack.com/tires/tirete...e.jsp?techid=7 http://www.discounttiredirect.com/di...nfoTireMath.do |
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12-31-2015, 10:15 AM | #19 | |
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I had 2 E70 X5s, now X5M with DWS with 275/40/20 front and 315/35/20 rear. I even had an F10 and F02 with DWS. They're solid. It snowed 14+ inches one year (within hours) in KC with a sheet of ice under the snow, my E70 with DWS gotten around very safely (felt very confident). I've driven my X5s with DWS on multiple snowboarding trips to the Vail/Copper, even took it offroad a few times. Never once do I feel that the car struggled or gotten stuck. I like the staggered for the look and performance as well. It only snows 5 times per winter in KC, so rolling around in true winter tires would make my car less enjoyable on the nice days. (winter tires have speed limitation, not that I go faster than 110mph - wink) On wheel width, as long as you're staying within the wheel width recommended by the tire manufacturer then you are fine. Slight variance isn't going to be detected by the ECU. The BMW ECU has a threshold around 1%. Any delta of more than 1% between front and rear, it will throw a code. The Porsche guys actually prefers to stretch their tires a little for better road feel. Their OEM would use 295s on 11" wide wheels (i.e. 991 Carrera 4S 19" setup), but BMW uses 315s on 11" wide wheels like on the non-M X5s . Porsche knows a thing or two about road feel. =) Sorry about the wait on your set. If I were you, I would demand a partial refund or something for your wait. Just call BMW NA, keep complaining and escalate until you get something for your hassle.
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Last edited by JNoSol; 12-31-2015 at 10:25 AM.. |
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01-13-2016, 08:07 AM | #21 | |
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Front: 21x10 ET40 Rear: 21x11.5 ET38 Using the OEM rear for the front will stick out 22m and reduce your suspension clearance by 18mm. Assuming it will clear the suspension (which it should), it would look good if you also throw in a 20mm spacers in the rear. This would be a very aggressive setup.
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01-13-2016, 08:37 AM | #22 |
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well, finally got the 20" OEM Winters yesterday... Was told that the dealer had to cancel many people's orders due to lack of supply. That is pretty pathetic, IMO. Gotta say that I'm somewhat regretting not going with JNoSol's setup as it looks better than the OEM 20s for Winter, and I'm sure it would handle well enough in nearly all weather that I'd be driving in anyway. Plus I would've received them sooner. Ouch.
I took a couple of crappy iPhone pics of the OEM 20s next to the OEM 21s for those wondering how the 2 compare... Happy driving! https://drive.google.com/file/d/10F7...ew?usp=sharing https://drive.google.com/file/d/18RU...ew?usp=sharing |
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