colinc Posted January 20, 2008 Report Share Posted January 20, 2008 Hi all Excuse me for being a bit uninformed here but perhaps you can answer a couple of questions for me or at least offer some advice. Reading various posts about runflat tyres etc, the opinion look a bit split with a bias toward conventional tyres. Assuming that I decided to replace the current rubber with conventional tyres, In my simple mind, the first question that arises is, what do I do if I get a puncture? i.e. no spare and possibly a wrecked rim. What do you guys do or is it just hope for the best. Second question, If I change from runflat, is it best to keep the same profile tyres as the originals (currently 255x35 and 225x40 on 18's)? My thinking is that I would probably keep the exising runflat tyres on the current rims and replace them with complete new wheels and tyres so I would have a little flexibility in sizes. I would also still have a complete (original) set to re-fit when I come to sell the car (not for a good while yet) Thanks for reading and I look forward to the replies CC Link to comment Share on other sites More sharing options...
gizze Posted January 20, 2008 Report Share Posted January 20, 2008 If you like your wheels I would swap for normal tyres as soon as you can and before you get to 4mm remaining so you can put them back on when you sell them. The whole principal of a run flat is to get you off a main road and to somewhere safe where you can get your tyre replaced and carry on your journey with very little hassle. Unfortunately trying to get to somewhere which actually has a tyre in stock is a nightmare, most people end up borrowing a car and getting BMW to replace the tyre, this costs a fortune and can take up to two weeks. So at the moment it seems like a complete balls up to me. Hardly any where will repair a run flat either, so it is always a new tyre. A compressor and a can of tyre sealant does exactly the same job plus you get all the benifits of handling and comfort too, plus if you do get caught short the chance or getting a regular tyre is far greater than trying to track down a run flat. So you tend to find you are on your way far quicker. Halfords do a really good compressor for £29 and a can of tyre sealant for £7. If you keep the same size wheel then yeah keep the same size tyre, if you go up a size buy accordingly. Link to comment Share on other sites More sharing options...
tinka Posted January 20, 2008 Report Share Posted January 20, 2008 i managed to get a 17" space saver,as i did'nt want to rely on just a mobility kit,as they do have limitations. only thing is its resting in the boot on show. Link to comment Share on other sites More sharing options...
Golfer Posted January 21, 2008 Report Share Posted January 21, 2008 What size space saver would you need for the 6 series on those 19" sport wheels?. 17" might be too close to the disks and not fit. Link to comment Share on other sites More sharing options...
gizze Posted January 21, 2008 Report Share Posted January 21, 2008 Not sure? Has it got a wheel well?? Link to comment Share on other sites More sharing options...
highflyin Posted January 21, 2008 Report Share Posted January 21, 2008 A recent quick story of my experience with BMW factory fitted run-flats that might help your decision making. Spent the last week doing 50 mile plus journey's up and own the motorway at mostly 85mph+. (actually 95)noticed that there was more than the usual slght vibration through the steering so thought one of the front wheels had thrown a balance weight. Took it into the tyreshop on Saturday for a balance. Technician removed the wheel, instantly noticed a small nail right through the tread, checked pressure in the tyre and it was down to 10psi, should be 36psi. Spent four hours of Saturday driving around looking for replacement run-flat. Eventually found one - but returned home to very pissed-off family who were looking to spend the day with me. A couple of things strike me about this experience: First, the on-board puncture alert display didn;t alarm the puncture as the system was designed (probably because it was a slow puncture - but who knows). Secondly, because there was no visible signs of a puncture and no drastic handling issues I have been driving at over 80mph effectively on a flat front tyre for over week. Lastly, matching run-flat makes to each axle means real hastles when you pucture one - because as was already said you have to wait 2-3 days for the shop to get a matching replacement. Hope this helps. If I get another BMW I'm definately going to remove the run-flats and have normal rubber, quite apart from the appaling ride quality they produce - which is unacceptable by today's standard - I read that statistically you'll get a puncture only every 90,000 miles, which kinda throws the business case for run-flats outa the window. Link to comment Share on other sites More sharing options...
Golfer Posted January 21, 2008 Report Share Posted January 21, 2008 [ QUOTE ] Not sure? Has it got a wheel well?? [/ QUOTE ] I dont know yet, I did not check under the floor cover......... anyone know?. Link to comment Share on other sites More sharing options...
Golfer Posted January 21, 2008 Report Share Posted January 21, 2008 [ QUOTE ] A recent quick story of my experience with BMW factory fitted run-flats that might help your decision making. Spent the last week doing 50 mile plus journey's up and own the motorway at mostly 85mph+. (actually 95)noticed that there was more than the usual slght vibration through the steering so thought one of the front wheels had thrown a balance weight. Took it into the tyreshop on Saturday for a balance. Technician removed the wheel, instantly noticed a small nail right through the tread, checked pressure in the tyre and it was down to 10psi, should be 36psi. Spent four hours of Saturday driving around looking for replacement run-flat. Eventually found one - but returned home to very pissed-off family who were looking to spend the day with me. A couple of things strike me about this experience: First, the on-board puncture alert display didn;t alarm the puncture as the system was designed (probably because it was a slow puncture - but who knows). Secondly, because there was no visible signs of a puncture and no drastic handling issues I have been driving at over 80mph effectively on a flat front tyre for over week. Lastly, matching run-flat makes to each axle means real hastles when you pucture one - because as was already said you have to wait 2-3 days for the shop to get a matching replacement. Hope this helps. If I get another BMW I'm definately going to remove the run-flats and have normal rubber, quite apart from the appaling ride quality they produce - which is unacceptable by today's standard - I read that statistically you'll get a puncture only every 90,000 miles, which kinda throws the business case for run-flats outa the window. [/ QUOTE ] Not a good experience, I have not suffered a flat tyre for many years, I will make some enquiries. Link to comment Share on other sites More sharing options...
colinc Posted January 21, 2008 Author Report Share Posted January 21, 2008 Hmm lots to think about there, looks like lots of reasons to change so I must get investigating the options and costs. Anyone know how the tyre pressure monitor is supposed to work? I've read of 2 different systems, one with pressure senders in each wheel and one where they use the ABS sensors to detect rpm differences between the inflated and deflated tyres. Which (if any of these) do BMW use. I would hazard a guess that, given the terrible over-tech idrive, they would go for the the latter.[/cynic off] Link to comment Share on other sites More sharing options...
edo Posted January 21, 2008 Report Share Posted January 21, 2008 As far as I know bmw system is using abs sensors, nothing physical in the wheels. Link to comment Share on other sites More sharing options...
CMC950 Posted January 23, 2008 Report Share Posted January 23, 2008 Frankly I think the debate about run-flats is another opportunity for the purists to harp on about the good old days. The same people who think that a DSG gearbox is the transmission of the devil! The reality is that the difference in handling is miniscule. BMW set up the suspension softer, specifically to compensate for the run-flat tyres. I think most people are confusing the 'harsh ride' with the fact they are driving an M-Sport car which comes with stiffer suspension and 18' wheels on 35 profile tyres. Hardly a recepie for tranquility, run-flats or not. And this inconvenience of driving around looking for a dealer who stocks the appropriate run-flat tyre is hardly worse than changing a front wheel in freezing rain on a b-road in Scotland at 6am in the morning. Lets also not forget the advantages of space and weight saving. Welcome to the future. Leave the run-flats alone! Link to comment Share on other sites More sharing options...
gizze Posted January 23, 2008 Report Share Posted January 23, 2008 [ QUOTE ] Frankly I think the debate about run-flats is another opportunity for the purists to harp on about the good old days. The same people who think that a DSG gearbox is the transmission of the devil! The reality is that the difference in handling is miniscule. BMW set up the suspension softer, specifically to compensate for the run-flat tyres. I think most people are confusing the 'harsh ride' with the fact they are driving an M-Sport car which comes with stiffer suspension and 18' wheels on 35 profile tyres. Hardly a recepie for tranquility, run-flats or not. And this inconvenience of driving around looking for a dealer who stocks the appropriate run-flat tyre is hardly worse than changing a front wheel in freezing rain on a b-road in Scotland at 6am in the morning. Lets also not forget the advantages of space and weight saving. Welcome to the future. Leave the run-flats alone! [/ QUOTE ] Load of cobblers. I have had 4 cars that came shod with run flats, and swapping to proper tyres not only improves the comfort factor 100x it also increases the way the car performs and handles. The M-Sport suspension is a Bilstein shock and Eiback spring, it is actually quite a soft combination for a sports set up, and an incredibly good strut too and a very progressive spring, and when you get proper tyres on the car you realise just what a superb set up it is for every day driving with the occasional blat on country roads. Even going from 17" run flats to 19" non run flats the comfort improves, this just proves that it is the tyre that is causing the problems. Oh, and I love the DSG gearbox, think Audi manuals are a load of shite! Clucth pedal too high, throw too long and not the smoothest of throws. Link to comment Share on other sites More sharing options...
moggle Posted January 23, 2008 Report Share Posted January 23, 2008 I have a E91 325 d SE model with 17 inch wheels and Bridgestone run flats. The handling is very good and the comfort is more than acceptable. My last car was a 2004 A6 1.9TDI which was as responsive as a canal boat, but suited me at the time. gIzzE, do you know what the suspension set up is on the SE models? I am a fan of the DSG, other car is a 2.0TDI Touran, the changes are so smooth and quick. Pitty the DSG is not capable of transmitting more than approx 250lb/ft torque, although I believe VAG are developing new units. Link to comment Share on other sites More sharing options...
gizze Posted January 23, 2008 Report Share Posted January 23, 2008 SE model uses a strut supplied by Sachs, doesn't soak up potholes etc. as well as the Bilstein strut. And I agree, we are all moaning about this generation BMW vs the last generation, however, for thos of us coming from say an Audi they are still very good, the way Audi manages to get their cars to crash over every lump and bump on the road and then wallow as badly as they do on the corners is an amazing feat in itself!! But going back to say an E39 5 series sport and an E46 3 series SE or sport shows you just how good it can be out of the box, all round handling really is amazing on those cars. Link to comment Share on other sites More sharing options...
Merlot Posted January 23, 2008 Report Share Posted January 23, 2008 [ QUOTE ] As far as I know bmw system is using abs sensors, nothing physical in the wheels. [/ QUOTE ] Correct, just like the cheap system available on transverse engined Audis' and VW's - its certainly crap on VAG stuff. Link to comment Share on other sites More sharing options...
gizze Posted January 23, 2008 Report Share Posted January 23, 2008 The US gets a pressure monitor system, you can buy the vales for around £150 for each corner. Link to comment Share on other sites More sharing options...
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