BMW run flat tyres - what a joke!
Discussion
Funk said:
BMW are now making runflats a cost-option on the 1-series (with the exception of the 135i and 123d) so evidently there's no issues with using regular tyres on the car. I was in the 'probably-shouldn't-do-it' camp but if BMW aren't worried about it, then I'd not be either. The only thing is that a RFT will get you home whereas a can of gunk may not.
My understanding was the cars computer could be programmed for either runflats or regular tyres, no? I thought problem was using regular tyers when the car thought they where runflats.mickeyboy said:
They also state the system they use to advise on pressure only tells you if you have a puncher so what happens if you have slow puncher you keep driving on a tyre until all the air has gone!
I had a tyre that used to lose pressure slowly on my 3 series and the warning light used to come on at around 28PSI I think. There's no way it would let you get down to zero pressure without warning you. You just have to remember to reset it when you air up.Webber3 said:
mickeyboy said:
They also state the system they use to advise on pressure only tells you if you have a puncher so what happens if you have slow puncher you keep driving on a tyre until all the air has gone!
I had a tyre that used to lose pressure slowly on my 3 series and the warning light used to come on at around 28PSI I think. There's no way it would let you get down to zero pressure without warning you. You just have to remember to reset it when you air up.va1o said:
My understanding was the cars computer could be programmed for either runflats or regular tyres, no? I thought problem was using regular tyers when the car thought they where runflats.
Ive got a 1 Series and recently made the change to conventional tyres and it most certainly won't be going back onto runflats, so much better in every way on conventional tyres and absolutely no issue with the pressure sensing capability.There's no change to the computer required (or possible AFAIK), the pressure "sensors" don't even exist as such, its just the computer monitoring the wheel speed sensors that are used by the ABS etc as well. You set the system when the tyres are inflated and you're driving normally, then if a tyre goes down the rolling radius of that wheel reduces so the wheel will be rotating slightly faster compared to the others, which triggers the alert. Therefore, if anything the sensors will work better with conventional tyres that have slightly softer sidewalls, as the rolling radius will change more for a given pressure drop.
In fact from what Ive seen, runflats and pressure sensing are far from infallable and could be just as dangerous as a conventional blowout in certain circumstances anyway. A neighbour of mine had a friend visit who also owned a 1 series. On the way over, the car indicated a rear puncture about 5 miles from our place so he stopped, had a quick look, couldnt see anything obvious so continued the last 5 miles at or below the BMW advised speed. When he arrived myself and the neighbour had a close look and although it looked OK from the outside, the tyre had completely delaminated on its inside edge to the extent that you could get your finger between the tread and the carcass where the steel bands were! Considering its a runflat there's no way all that damage happened in such a short distance so we can only assume it had been flat for quite a while but the pressure warning was rather delayed due to insufficient change in wheel speed. The problem with that is that many would carry on driving for the prescribed 100-150 mile limits based on when the computer warned them, but in this case there's no way it would have lasted that long before completely destroying itself!
Edited by LocoBlade on Thursday 5th March 20:47
tom g said:
mickeyboy said:
They also state the system they use to advise on pressure only tells you if you have a puncher
I have to say that I suspect that the Ultimate Driving Machine isn't really if BMW make such poor choices about the boots they use. Didn't anyone at that company test them or were they the test pilots too busy trying to disable the indicator stalk to notice that RFTs are such a poor tyre?
My car arrived with 19" M-sport on run flats and I wanted to put some winter rubber on. Not possible with 19" as my tyre fitter couldn't get them. I bought some 18" SE and the only tyres he could get were Pirelli for the rear and Kumho for the front both non run-flats. The ride is a lot better and the handling is just superb with excellent corner hugging ability.
In a couple of months when the 19" go back on I'm going to take the run flats off (and with them only doing 9k miles they are still good to sell) and I'll put some nice grippy summer conventional tyres on.
I have a can of Tyreweld, compressor, jack and plug kit if I get a puncture.
In a couple of months when the 19" go back on I'm going to take the run flats off (and with them only doing 9k miles they are still good to sell) and I'll put some nice grippy summer conventional tyres on.
I have a can of Tyreweld, compressor, jack and plug kit if I get a puncture.
Mr Green said:
elfer said:
btdk5 said:
BMWBen said:
I've got runflats on my 5er - was fully expecting to have to replace them straight away due to extreme crapness, but actually they're fine.
??
Wait till they wear out then try normal tyres. The ride quality will improve 10 fold.??
Saying that you rarely have to change all 4 at once, which is quite costly so if it doesnt bother you why do it.
Unless he has bigger tyres on the back.
.
drover41 said:
I am thinking about buying a bmw with RFs - is it feasible to carry a spare tyre so others could fit it onto the wheel?
I think you'd be better off factoring in a set of real tyres and some good breakdown cover in the cost of the sale.Not on 19" wheels is it? If it is search for the watchdog bmw 19" wheels cracking thread.
You would be better taking the rft's off selling them on Fleecebay and putting proper PS2's or Conti's on. All you need is a tin of tyreweld, some of those screw-in plugs and a compressor.
I went the whole hog and got a jack as well as it makes it easier finding the screw/nail and removing it.
I went the whole hog and got a jack as well as it makes it easier finding the screw/nail and removing it.
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