04-17-2015, 02:55 PM | #1 |
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Advice on changing run-flats on 2015
I have an 2015 X1 M Sport Trim and very much dislike the Pirelli Run-flats Cinturato P7 all season 225/45 R18 tires that are stock on both the front and rear tires. I am very tolerant of a stiff ride but even for me these tires are totally unreasonable as they make the car so uncomfortable on even the slightest of a bump on the road. California highways have a high frequency of these types of road level imperfections so there is no joy in driving as we would expect from a BMW.
I have done a considerable amount of research and even contacted BMW USA, International Headquarters, and the service unit of the dealer where I purchased. Frankly, my impression is that I know more about the technical situation and possible remedy than they do. NO HELP AT ALL other than that "BMW does not recommend anything other than run-flats", and that you may jeopardize your car warranty by replacing (car has 5800 miles on it). Believe that BMW will lose allot of customers in the future with these unacceptable run-flats. These Pirelli run-flats have no "forgiveness" nor shock absorbing; very stiff and hard as a rock at recommended pressures. My research points toward replacing with the non run-flat version of the same Pirelli Cinturato tire 225/45 R18 with either the 91V or 95V rating; the specifications are nearly exact between the run-flat and non run-flat version ties. The non run-flat tire is exceptionally highly rated in all relevant categories ( fromTire Rack and similar type website). I am thinking of the 95V version as I have the X1 M Sport suspension that is stiffer than the standard. Any advice or experience would be greatly appreciated. |
04-17-2015, 03:21 PM | #2 |
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One of the first things I'm doing when I take delivery next month is swapping out the wheels/tires for non-RFTs. This is a pretty common change. I can't imagine it actually affecting warranty, but I can't say that I have any experience in dealing with that situation. Given that BMW already offers multiple different stock wheel/tire fitments for the X1, swapping them to suit your preference really doesn't seem like a big deal at all.
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04-17-2015, 03:34 PM | #3 | |
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Not sure if it is a significant consideration but cautious
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04-18-2015, 07:04 AM | #4 |
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Get whichever tire you prefer, and keep one of these back where the spare tire should be: http://www.tirerack.com/accessories/detail.jsp?ID=38
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04-18-2015, 09:57 AM | #5 |
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I know my post won't be popular but just wanna put my 2 cents out there. When we bought a brand new 2007 Lexus roadster for my wife to drive, yes I experience the stiffness but she never did cause she got nothing to compare it with and the peace of mind when she gets a flat tire and continue driving with it (50mph or less) is priceless. Fast forward last November, our son starts to drive and wifey wants a suv that they can share so we bought a 2015 X1 M Sport with 19 inch M Sport / run flats. I know the folks in the dealership so the only advise they gave me is to get the extra warranty for run flat tires for like $8/month for 5 years. Again, my son and wife don't know the difference and they thought the vehicle drives so nice. After first month of driving it, a rock (baseball size) flew out of the truck and coming towards me while driving 70mph and tried to dodge it but the rear driver side wheel caught it. Right away, all kinds of warnings flashing on the dash. It also say it's safe to drive the vehicle still but must drive 50mph or less. At that time, dealership is 15 miles away and decided to bring it there to replace it. They replaced with no charge cause of the tire warranty we have and the invoice shows that it should have been a $440 charge.
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04-18-2015, 12:34 PM | #6 |
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04-18-2015, 01:16 PM | #7 |
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That's probably why BMW doesn't want you to use regular non-RFTs. They don't want your car telling you it's safe to drive when it really isn't.
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04-18-2015, 10:54 PM | #8 |
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Run-flats are they really safe?
Interesting, read numerous reviews of run-flats and impression are that they are less safe because of much higher frequency to get a puncture compared to non-RFTs. All the reviews did not recommend run-flats implying that they are less safe because of the increased likelihood of punctures, excessive wearing, and lower mpg because of the extra road friction.
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04-20-2015, 12:46 PM | #10 |
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I do not agree with most people on this topic.
I replaced RFT tires on my BMW 328i with regular all season tires. The car driving dynamics changed a lot. It was like a train on rails with RFTs. With non RFT it was more like a Toyota. Now, I believe there are a bunch of people who actually like the way a Toyota drives (it is one of the most popular cars, anyway), but THINK they like how a BMW drives. These people will definitely like a switch to non-RFTs. Basically if you want BMW looks with Toyota driving dynamics replace RFTs with regular tires by all means. Otherwise stick with RFTs. You can go to a smaller size if you have bad roads or want more compliance. An X1 on 17 inch OEM wheels is pretty compliant for a BMW. If you still cannot tolerate it then you are in the Toyota category. With non-RFTs you loose a lot of steering precision. The car will roll in corners and dive under braking. Just think about it, what gives you the added comfort and cushioning? The tires allow more deflection. The same deflection will cause handling to deteriorate. The loss in steering feel was horrible in my opinion. |
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04-20-2015, 12:57 PM | #11 | |
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The dealer inspected the tire and decided that it is structurally sound. I drove another 12k miles on that tire (I know they should have changed it). Also, my mileage dropped when I switched from RFT to non RFT. This is counter intuitive, although RFTs are heavier, they maintain their round shape better, therefore they have lower rolling resistance. Again these are based on my personal experience, I would never change to non RFTs on a BMW, unless the suspension is tuned for non-RFT tires. |
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04-20-2015, 01:02 PM | #12 | |
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04-20-2015, 01:32 PM | #13 |
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I think you have to be very naive to think BMW designed the suspension without taking the stiffer RFT tyres into account.
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04-20-2015, 01:57 PM | #14 | |
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04-20-2015, 02:09 PM | #15 | |
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I am super happy with my ride quality and will try to keep it that way. M Sport was a bit hard for me, so i toned it down one level to Sport Line. But in the end i support changing things if you do not like it. |
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04-20-2015, 02:20 PM | #16 | ||
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04-20-2015, 02:31 PM | #17 | |
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BTW my car was a pre-facelift 2008 328i with sport package, so the suspension was really stiff with RFT tires. With non-RFT it was closer to a Toyota than a BMW. Things improved a bit when I increased tire pressure to 42psi all around. But still there was no comparison with RFTs. There is an on-ramp from 92 east bound to 880 south bound in Hayward. I take this on-ramp regularly during my commute. It is sloping down with a curve at the end just before merging with 880 SB. With my 328i sport package and non RFTs, I had to slow down before the curve and the car would dive on front wheels during braking. I almost crashed once I tried to take this without braking. With my X1 xDrive 28i with 18 inch sport line RFT Contis, I can take this corner without braking. The car feels rock solid. An SAV with high center of gravity and non-sport suspension handles better than a sport-package 3 series. The steering is more precise. With non RFTs I felt the wheels turn and the car keeps going straight. Just as said above you can't have your cake and eat it too. The softer ride comes at expense of lost steering feel and handling. |
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04-20-2015, 02:46 PM | #18 |
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Bridgestone Driveguards
I have had the Driveguards on my 35i since late February and they are more forgiving than either OEM Pirelli or Continental RFTs. They were good in light snow and rain as well and resistant to tram-lining. They absorb road impacts better and not so jarring as the two tires mentioned above. A nice buy.
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04-21-2015, 10:47 AM | #19 |
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We will be replacing the Pirelli RFT P7s that has a 91V rating on our X1 MSport 2015 with the Pirelli non-RF P7 All Season Plus that has a 95V rating. My reasoning that with the stiff suspension, I needed a non-RF stiffer sidewall and hence the 95V. Yes am worried about the handling around curves and hopefully it does not change too much the driving dynamics around curves, but will (again hopefully) give a softer ride. The RFT are just too unforgiving in giving a harsh ride, hard as a rock at recommended pressures! Willing to take the chance and I believe that most will agree that the RFT gives too hard, stiff a ride.
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04-21-2015, 11:19 AM | #20 |
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I just recently installed new non RF summer tires, and the difference is VERY noticeable. Less harshness and noise are the biggest difference, but handling is crisper, with less apparent understeer. I went with 245-40/19 fronts, and 275-35/19 rears on staggered width wheels. I chose Continental Extreme DW on Niche wheels. All this talk of engineering by BMW to allow for RF stiffness is a smoke screen (IMO) to hide the fact BMWs no longer have to allow the storage space reserved for a spare, and of course, the added weight. If you choose a proper performance tire, all facets of the driving experience improve.
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04-21-2015, 11:41 AM | #21 | |
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04-21-2015, 02:12 PM | #22 |
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