ISUK

I had a puncture last week and took my car into my local tyre dealer for a replacement. The car has done 16,600 miles and the rear tyres are on the wear bars now. I decided to stick with the Dunlop run flats as they did a faultless job in letting me drive round with a puncture.

The cause of the flat was a small nail but when they took my tyre off they discovered an 8" gash in the sidewall on the inner side of the tyre.

I have no idea how it got there as I never park my car on kerbs and the tyre shop guys were speachless that the tyre hadn't shredded itself. They have kept the tyre and are going to give it to the Dunlop rep on his next visit.

One thing that I did find disapointing is that although i-drive warns you of a puncture, it doesn't tell you which wheel is affected. Iceman, maybe you can point out this flaw to your contacts at BMW or advise if version 13.3 fixes this issue.

Rudy

That's not a 'flaw,' it's a limitation. I doubt any software fix will enable this the way you describe.

The way that most manufacturers implement tire pressure monitoring is by using existing wheel rotation sensors, etc. Using these sensors, they can only determine that there is a significant variance in rotational speed of a tire relative to the others. It's an inexpensive way to implement one of these systems (which I think may be required for SUV's in the US now).

The better systems include an actual pressure transponder mounted inside each wheel that continually transmits the exact pressure of that tire back to a central unit. These systems can tell you exactly which tire is low and by how much, etc. They are much more expensive to install and therefore are only found on higher-end cars.

ISUK

Thanks for the response Rudy. I was aware from my Z4 that BMW have put a relatively cheap system on their cars but it stands to reason that if the sensor detects a change in rotational speed it must know which wheel it is sensing has changed.

P.S. I regard the 5 series as a "high end" car in the UK. We have Fords and Renaults here which are far cheaper and have individual tyre pressure sensors fitted as standard.

browellm

....and Renault Lagunas

Mark-Yorkshire

ISUK,
I had been wondering what I would do if I had a puncture. With previous cars if the puncture was not on the sidewall I had tyre mended at Kwikfit for a small sum but I guess most operators like Kwikfit do not have the correct equipment for removing run flats without damaging rims. Did your BMW dealer replace the tyre themselves or sub contract the job out?- If contracted out do you know who they used?Was the alloy unmarked?
I think I will contact Dunlop Customer relations to find out what they recommend if a puncture occurs - no doubt they will say buy a new tyre which would be a very expensive puncture. Also if we are forced to buy new tyres from BMW dealer by virtue of Fast Fit operators not having correct equipment we will end up paying well over the odds for replacement tyre.
Mark-Yorkshire

ISUK

Mark,

I had my tyre swapped at my local independent tyre dealer who do all my truck tyres. They daren't upset me! The alloys are unmarked.

Most BMW dealers sub out tyre work anyway. Kwik Fit apparently have the best machines for removing run flats. The tyre fitter said the BMW rims on the 5 series are a pain as they have two inner raised grooves to prevent the tyre coming off the rim. He has changed a tyre on my Z4 before which is also a run flat and he said that was a doddle in comparison. It took two of them to get the tyre off the rim and a serious amount of brute strength. These things just do not want to come off.

I am seriously impressed at how well the run flat did it's job though. No drama and no noticeable affect upon the handling.

Mark-Yorkshire

ISUK,
At what speed were you travelling when puncture occurred? I must say it is reassuring to think that if a puncture occurred on the motorway there would not be any dramatic effect on handling. Interesting that your Z4 run flats came off easier than 530d - which make of run flats are on Z4 and 530d?
Mark

ISUK

Mark,

The Z4 runs on Bridgestones, the 5 is on Dunlops. The difference is the extra rims on the inside of the alloy on the 5. I think my puncture was caused by kids leaving a nail under my tyre in a car park. I had the car up to 75mph with no problem with the flat though. These things are incredibly hard and will not come off.

pbarch1

Have you'll seen the video of the 5er traving at about 120 mph hitting a spike strip and then runnign anouther twenty miles, All on RFT's very cool, it's just too bad the are so f$%#^ng LOUD !!! I just didn't buy a 5'er to sound like I'm driving a truck

browellm

Mark

I had a puncture warning on the motorway at 80mph. I could feel no difference in handling whatsoever - to the point where I thought the warning was a malfunction in the system! I was able to drive a further 400+ miles before getting the tyre replaced.