03-05-2018, 08:59 PM | #1 |
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Ideal Wheel and Tire Size
Hi. I am new to the forum. I plan to get a pre-owned m235i soon. I have a question regarding wheel and tire size. I've back read the past several pages of this section and did not seem to find the answer to my question. I am curious as to what the ideal wheel and tire size for handling is. Car will be used mostly for street driving and occasional track days, perhaps 2-3x a year. TIA!
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03-21-2018, 07:35 PM | #2 |
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all depends on what sort of driving conditions you want to adapt to.
The bigger the wheel the smaller the side wall, the harsher it'll be. whether you go 18" or 19" it totally up to you, but fresh out of the box M235/M240 RWD definitely need more meat at the rear, at least a 255 tyre, it'll ground more power. going one size wider in the front will help too, i feel the 225s are too narrow and will often slide if you corner sharply at speed. |
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03-23-2018, 10:12 PM | #4 |
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03-29-2018, 10:48 AM | #6 |
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03-29-2018, 10:58 AM | #7 |
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"Ideal" is dependent on what the user views as ideal. For me, the ideal street setup for the M235/M240 would be 18X8 with 245/35R18 in the front and 18X8/5 with 255/35R18 out back. That setup would give a solid blend of grip, neutral handling behavior with a slight push in the front, and some available slide and without wrecking handling feel, MPGs, or creating some odd darting/tramlining behavior because of excessive tire width. Of course, when it comes to tires for the street, Michelin Pilot Supersports and Sport 4s is where it's at, period.
I shopped long and hard for wheels and a tire setup for my M235. Lots and lots of people run 18X8.5 in the front and 18X9.5 out back and then stretch the stock tires to fit the wheel width; mostly in order to get the suspension and fender clearance they need. I'm not a fan of that approach at all. It's a bandaid. I ended going with Alutec Drive 18X8 et43 at all four corners. I'm currently running the stock 225/40 an 245/35 Michelin Pilot SS staggered setup on these wheels, but I will go with 245/35R18 Michelin Pilot Sport 4s at all four corners next year. I'd love to run slightly wider rims and tires out back, but they don't make these wheels in the 8.5 so I had to compromise. The offset is perfect and makes the setup look wider than it really is (especially out back) and the offset is such that I can run 245s in the front with no suspension or fender clearance issues. If this car has a handling issue, it's the narrow 225s in the front. The over 1" wider 245s will greatly enhance the handling feel and front end grip. The grip out back will have to be managed with throttle input and a mechanical LSD. As for track use, I wouldn't dare run street tires during a track day. Autox? Sure. Track day? No way. Street tires can get mostly destroyed in 1 hour of track use and that's pricey. I'd definitely have a 255 width track tire/wheel setup for track days.
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03-29-2018, 10:59 AM | #8 |
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There's no tire maker that recommends putting a 255 on a 8" wide rim. Not one. You can do it, but I sure wouldn't go tracking the car with that tire setup.
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03-29-2018, 12:10 PM | #9 |
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03-29-2018, 02:31 PM | #10 |
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Yes, the tire bead could separate from the wheel causing the tire to loose all pressure rapidly and/or the tire pull off the rim. There are other issues running excessively wide tires on narrow rims they weren't designed for, but the two potential issues I noted would be the biggest ones to be concerned about.
Just because you can, doesn't mean you should.
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04-10-2018, 04:35 PM | #11 | |
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Quote:
I'm still trying to figure out what I want to do for wheels in 18".
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04-11-2018, 07:16 PM | #12 |
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What’s the ideal rear wheel offset for an 18x9 in the 2? I’ve seen Apex recommend 18x9.5ET58 and 18x8.5ET45, so just splitting the difference it would be an 18x9ET52-53? I found an 18x9ET50 or an 18x9.5ET45 in a wheel I like...would either of those fit?
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04-12-2018, 11:12 AM | #13 |
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As I wait for my M240i to be built, I've been pondering wheel / tire upgrades myself and one of the things I've wondered is why folks would go with 19" rims when from all I've read they don't give any performance advantage but DO make the ride quality worse and are more prone to be damaged.
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04-22-2018, 03:17 PM | #14 |
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As for the 19"s, many people prefer the way they look. I'm not one of them.
There is probably a small performance advantage, but I wouldn't expect much. I would expect the ride to be worse and the wheels/tires to be more easily damaged. I'll stick with 18" wheels for the street. I did go with 17" for my track wheels/tires. I wish I had spent a little more and got some 18*8.5 or 9. |
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04-25-2018, 03:04 PM | #15 | |
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I don't think there will be any performance gain with 19" for 2 series. Mostly, larger diameter rim is for bigger brake (if not for looks). |
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04-28-2018, 08:17 PM | #16 |
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I'd recommend keeping as close to stock scrub radius on the 2 series. 18 or 19" wheels with 8" et45 up front and 9" et48 rear. 225-235 front, 245-265 rears tires.
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05-03-2018, 10:38 AM | #17 |
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Bigger diameter wheels (19" and up) will actually hurt handling somewhat, but probably not enough to notice on the street, because they are heavier. Also much more prone to tire damage w/ the short sidewall.
For handling it is better to put a smaller tire on a given rim, rather than having a loose/baggy sidewall that will let the tire roll over more (but this may give a slightly softer ride - the 245's are max for the 8" wheel). The MPSS is apparently very prone to this rollover edge-wear, but I'm a Conti fan and haven't tried them - my ExtremeSports held up well for my first day of track use (but if you can actually drive, you might put a lot more wear on them than I did ). And you might want to check out some of the 17" options if you plan to drive hard, track, or have bad roads. Lots of track cars use 245 on 17", and can clear the M-brakes OK - to me these don't look much different from the 18's. I think there is a set for sale in the NY/NJ regional forum to see how they look (and probably many others in the picture forums). |
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06-08-2020, 09:19 PM | #19 |
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I'm trying to get a staggered 245/40/18 & 265/35/18 MPSS to fit in there preferably without fender roll. What offset would I need for front and rear?
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06-14-2020, 06:23 PM | #20 |
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Could you tell me if these tires will work with my new wheels?
Currently I have Staggered Setup: Bridgestone RE-71R 235/40/18 FRONT 8.5 Bridgestone RE-71R 265/35/18 REAR 9.5 I'm switching to Square 8.5 on all 4 wheels. I know the front tires would work but will my rear tires fit? Will this be safe to run on the circuit track? If the rear tires didn't fit, would it be better performance to run a 245/35/18 on all four 8.5s for the track? I am XDRIVE if this matters. Ideally Id like to run my tires I already have. But I also want to know which size tire is most ideal for and xdrive on the track with my four 18in 8.5. Thanks for any clarification on this! Offsets and suspension is good. |
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06-14-2020, 06:47 PM | #21 | |
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I assume you could still run it, but I have no idea how safe it would be. Autocrossers, including successful ones, often match tires and wheels well out of the norm, and it works for them. A circuit track is a much different challenge for a tire, though. The general rule of thumb for matching tires to wheels when going to the track is that the tire's tread width be +/- 1" of the wheel width. In the case of the RE-71R, that puts the 245/40-18 in the sweet spot. Note that there is no 245/35-18 in RE-71R. Although I'd choose a 35-series over a 40-series for the track, I don't know how much difference it's going to make unless you're competing in time trials, autocross, or something like that. All else being equal, the tread compound trumps the series height. A tire tread width on the minus side of the +/- 1" range will provide the driver with crisper handling (e.g., a tire with 8.1" of tread width on an 8.5" wide wheel will generally have better turn-in characteristics than a tire with 9.1" of tread width on that same wheel). That generalization is widely accepted by track rats who have often tried quite a few variations while looking for the best combination of grip and steering feel. You too may well end up trying a number of combinations until you find one that you're satisfied with. Same thing with brake pads, tire compounds, and any other variables you choose to play around with (e.g., power, differentials, weight reductions, etc.).
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2017 M240i: 25.9K, 28.9 mpg, MT, Sunroof Delete, 3,432#, EB, Leather, Driving Assistance Package, Heated Front Seats | Sold: E12 530i, E24 M635CSi, E39 520i, E30 325is, E36 M3 (2)
TC Kline Coilovers; H&R Front Bar; Wavetrac; Al Subframe Bushings; 18X9/9½ ARC-8s; 255/35-18 PS4S (4); Dinan Elite V2 & CAI; MPerf Orange BBK; Schroth Quick Fit Pro; Full PPF Last edited by dradernh; 06-14-2020 at 07:02 PM.. |
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06-14-2020, 07:38 PM | #22 | |
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I have two sizes narrowed down, so what would you recommend? 245/40/18 square or 235/40/18 square The only reason I would consider the 245s is more traction. However the 235s are 1lb lighter and a more favorable tread width of 8.8" verse the 9" of the 245. Now I know if I was RWD I would chose the 245s, but since I make up in traction being AWD would the lighter 235s be a better choice? I could be being very nit picky and maybe this is all negligible Which ones should I get and call it a day? Last edited by SerenVoX; 06-14-2020 at 10:43 PM.. |
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