run flats
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I replaced my RFTs with non-RFTs and it was great. This was on my previous 2007 530i. My RFTs were constantly showing up as low on air in the TPM. Just get the right replacement tires. My new ones drove great, but they became very noisy after about 10,000.
Does anyone have any input as to whether the 18" Sport wheels are better off with the RFTs? I would think the harder compound protects the wheels given the short sidewall height compared to that of a Non-RFT, which I would imagine would give much more and increase the risk of breaking a rim upon hitting rough roads. Any thoughts?
I am hoping to switch out my RFTS, but will not if doing so will decrease the protection of the bigger wheels. THANKS
I am hoping to switch out my RFTS, but will not if doing so will decrease the protection of the bigger wheels. THANKS
I've searched the threads a bit more, and it seems an argument can be made the other way in that the run flat tires can cause damage themselves due to their hardened compound and lack of air compared to that of a pnumatic (sp) tire. It's possible that the cushion that can be gained from more air in a tire (as in a pnumatic tire) may be more protective to wheels than the RFTs.
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Where do you get the idea there is any more air in a non run flat tire? Run flats carry 34-42 psi (on my 535i) just like non run flats.
dj
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The pressure has nothing to do with the volume in the tire. Higher pressure with a smaller volume can result in less air being in the tire so it was a valid comment/question. If the run flat has the same psi and a smaller air volume.....it has less air.
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I get the pressure vs volume thing, I dealt with that sort of thing my entire career, so I'll ask you the same question, where do you get the idea there is any more air in a non run flat tire? Or any less volume in a RFT? :dunno:
dj
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985 Posts
If the outside dimensions are same and the run flat has thicker walls ( which they do) there would be less space in the non-run flat. Aside from that, the question regarding the run flat more likely to cause damage is a valid one. This is why BMW had to soften the suspension on the sport package with run flats...... the run flats are stiffer.
The run flat tire is simply not the right solution for a sports car or sedan...... too much of a compromise. I understand if it is for a generic sedan ( Camry, etc.) but the heavier and harder tire combined with a softer suspenion sound more like a setup expected in a pickup or old style SUV. Porsche has the right solution....... a normal high performnce tire with sealnt and compressor. ( I believe BMW does this also with the Z). I originally looked a 3 series but the deal breaker was the run flats. BMW's inability to design a 3 series with a space for a spare forced them to declare run flat tire as the trend for future......BS.
The run flat tire is simply not the right solution for a sports car or sedan...... too much of a compromise. I understand if it is for a generic sedan ( Camry, etc.) but the heavier and harder tire combined with a softer suspenion sound more like a setup expected in a pickup or old style SUV. Porsche has the right solution....... a normal high performnce tire with sealnt and compressor. ( I believe BMW does this also with the Z). I originally looked a 3 series but the deal breaker was the run flats. BMW's inability to design a 3 series with a space for a spare forced them to declare run flat tire as the trend for future......BS.
Run flats are filled with air, as a matter of fact it is required by federal law.
However they can run low/flat because of a very stiff side wall and other "heavy " features. That is what makes them ride very rough/noisy. I have them on my Corvette and yes they ride rough/noisy. most Corvette guys hate them, but on the Vette you have no spare so if you delete them you are on your own.
That said I can imagine a BMW with them. doesnt sound too good since they dont flex too well and will Buzz alot.
I would get rid of them and take a small risk. I havnt had a flat in years and usually they go flat in the driveway. With pressure sensors, they will give you some notice for punctures. If you hit a piece of iron etc, you have to call road service.
At least you had a great time. :rofl:
I am partial to Michelins. I think I would go there.
BTW from what I hear, the Michelin runflat seems a little better than others.
However they can run low/flat because of a very stiff side wall and other "heavy " features. That is what makes them ride very rough/noisy. I have them on my Corvette and yes they ride rough/noisy. most Corvette guys hate them, but on the Vette you have no spare so if you delete them you are on your own.
That said I can imagine a BMW with them. doesnt sound too good since they dont flex too well and will Buzz alot.
I would get rid of them and take a small risk. I havnt had a flat in years and usually they go flat in the driveway. With pressure sensors, they will give you some notice for punctures. If you hit a piece of iron etc, you have to call road service.
At least you had a great time. :rofl:
I am partial to Michelins. I think I would go there.
BTW from what I hear, the Michelin runflat seems a little better than others.
I know it's been a couple of weeks since this thread had begun, but thought that I would throw in my two cents worth... I just turned 32K miles on my OEM Dunlop RFTs and had them changed out. Personally, I like the idea of having the RFTs when driving at high speeds but thought the Dunlops were a bit rough. I priced out several brands from TireRack.com and spoke to one of my local tire shops who actually beat their prices (by a lot)! I decided on the Michelin RFTs and I have really noticed a change in the ride. They definitely ride much smoother and quieter than the Dunlops and have a similar speed rating...
+1. Funny how everyone who rates a new set of tires always notes how much quieter they are than the set they just replaced. My experience is that the closer a tire gets to its wear limit, the noiser it gets. I've never had a new set of tires that was noisier than the ones I took off - regardless of style.Brand new tires are always gonna start out quieter.:dunno: Give them a while and report back.
dj
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