BMW and Run flat Tyres

[gizlaroc]

DSM2 said:

dxb335d said:

I dont remember complaining about cracked rims? I have found the ride and handling better with non-runflats.

My apologies is was mda335i. Sorry about that.

Anyway, point remains, RFTs are a lot different to normal tyres. I think most people find the ride much better without RFTs and maybe think tha handling's better too. Problem is most owners don't ever get near the limits of the car and if in some circumstance they did..................

Yeah you would see that run flats can be bordering on dangerous!!


Seriously the only time run flats are better is on a very smooth surface when straight line braking. Run flats are causing some real problems, ask the insurers, the higher pressures are causing stress fractures on both wheels and subframe arms etc.

I agree though that you should tell your insurer, you would be an idiot not to.

[islander]

NickB12 said:

It feels more secure over wet and bumpy roads as well, where it used to skip sideways, unnervingly so, before.

I have a 55plate 525d MSport with just over 70k on the clock, when I took it in for a service I complained about this and when I collected it they had replaced all 4 tyres and swopped my front wheels for my rear.

I am suspecious of this because this is the second time I have had all four tyres replaced at the same time due to the same vauge steering, the first time was at a Kwik Fit and whilst they were replacing the rears I had a close look at the fronts and found the outside of the tyre was out of round (Spun the wheel and watched the gap between the tyre and the wheel arch), it was a long way out! Anyway replacement tyre and balance solved the problem!

Again after the second replacement set of tyres the problem has gone away.

I have also spoken to very good and reliable source who has said that the fleet of white BMW's that he runs has had all these type of wheels replaced because they were going out of round, and this had nothing to do with the blue lights on top of the cars

Could new tyres, and a rebalance solve an M Sport wheel problem?

[rich_vw]

Hey there, recently i've been keeping an eye on the BMW section as i'm due to pickup my first within the next week! I'm getting a 118d M Sport with a few additional items including the wheel upgrade! Are the run flats really this bad or is it all isolated?? Also what damage can/has been caused to wheels, i'll be damed if i'll be putting up with that when spending (for me anyways) a large sum of cash.

Cheers,

Rich

[DSM2]

rich_vw said:

Hey there, recently i've been keeping an eye on the BMW section as i'm due to pickup my first within the next week! I'm getting a 118d M Sport with a few additional items including the wheel upgrade! Are the run flats really this bad or is it all isolated?? Also what damage can/has been caused to wheels, i'll be damed if i'll be putting up with that when spending (for me anyways) a large sum of cash.

Cheers,

Rich

No they're not that bad, but the ride is harder than with non RFTs.

Most of the wheel damage is caused by fitters using the wrong technique/equipment when removing worn /damaged tyres.

Whilst I am aware of lots of those incidences, I am unaware of any genuine wheel damage attributable to the tyre itself.

[rich_vw]

DSM2 said:

rich_vw said:

Hey there, recently i've been keeping an eye on the BMW section as i'm due to pickup my first within the next week! I'm getting a 118d M Sport with a few additional items including the wheel upgrade! Are the run flats really this bad or is it all isolated?? Also what damage can/has been caused to wheels, i'll be damed if i'll be putting up with that when spending (for me anyways) a large sum of cash.

Cheers,

Rich

No they're not that bad, but the ride is harder than with non RFTs.

Most of the wheel damage is caused by fitters using the wrong technique/equipment when removing worn /damaged tyres.

Whilst I am aware of lots of those incidences, I am unaware of any genuine wheel damage attributable to the tyre itself.

Thats good then, harder ride doesn't really bother me too much just wanted to be aware of what I needed to look out for, now I know its te fitter.

Cheers

[NickB12]

rich_vw said:

Hey there, recently i've been keeping an eye on the BMW section as i'm due to pickup my first within the next week! I'm getting a 118d M Sport with a few additional items including the wheel upgrade! Are the run flats really this bad or is it all isolated?? Also what damage can/has been caused to wheels, i'll be damed if i'll be putting up with that when spending (for me anyways) a large sum of cash.

Cheers,

Rich

I'm afraid to say I think they are pretty bad imho. I have a 07 120D M Sport and have changed to non rft because I felt I just had to.

On smooth dry surfaces the ride was firm but positive, good turn in, with good grip. But when the road was wet and/or bumpy it felt like it was going to disappear into the scenery at every bend. It just skipped over any unevenness.

There's a route I often take where there's a drain cover on a slight bend and it'd skip sideways over that. The final straw was coming round a slight bend @ 40mph in the dry to find a huge truck doing an imaginative manoeuvre. I braked hard and went straight. That was it for me.

I appreciate all opinions are subjective, fair enough, and this is just my opinion. But if you consider I had a TVR for 9 yrs, and have had a Z4 with rft's for 4, neither of which scared me the way the 120 on rft's did, then you'll see the perspective I'm coming from.

[rsvaprilia]

Just had a test drive of a 135i. I assume it had run flats on it. The road holding & comfort levels didn't seem to be a problem over some pretty bumpy B & C roads in N. Yorks. moors & this included a lot of wet miles as well. I wasn't going wild but was certainly motoring & didn't notice any problem with turn-in or braking.

[recalluk]

One thing I have noticed, there is a WORLD of difference on the make of RFT.

My 08 plate 320i has Conti SSR on it and its fine .. tiny bit harsh but not so much.

Identical car to colleague has the Bridgestone on it, and God its awful. I couldn't live with that. We are both at identical pressure. Needless to see he is off to get his swapped for Conti .. ASAP.

By all accounts Michelin are good too.

[dxb335d]

DSM2 said:

dxb335d said:

I dont remember complaining about cracked rims? I have found the ride and handling better with non-runflats.

My apologies is was mda335i. Sorry about that.

Anyway, point remains, RFTs are a lot different to normal tyres. I think most people find the ride much better without RFTs and maybe think tha handling's better too. Problem is most owners don't ever get near the limits of the car and if in some circumstance they did..................

On track i foudn the Non runflats sublime. No issues, handled very well.

Edited by dxb335d on Tuesday 8th July 21:01

[Methane Bloke]

Well both our run flat equipped BMs are on Michelins now and I wouldn't use anything else. Since changing from Bridgestones on the 120d I haven't seen the traction light come once. The ride is better on the 335d than it was on our previous 330d e46 (which was on Bridgestones).

Regards

Chris

[King of Dings]

I’ve had loads of 3 series of every kind 328 / 330 / 318 / 320d all non run flats, great cars handle brilliantly. Done 80k plus in all of them.

Currently have a 320d touring on RFT’s and they’re blumin awful to the extent that it makes the family car sick.

They also wear out really quickly and cost a lot more to replace. They are extremely difficult to balance correctly meaning there is always minor wheel / steering vibration at motorway speeds.

I drive motorway, A / B and un classified roads almost every day. The only road they are adequate on is motorway. The rest they are a total waste of time and take motoring, ride, handling and comfort back 20 years.

I won't buy another BMW while they continue to fit run-flat's.

[DSM2]

King of Dings said:

I’ve had loads of 3 series of every kind 328 / 330 / 318 / 320d all non run flats, great cars handle brilliantly. Done 80k plus in all of them.

Currently have a 320d touring on RFT’s and they’re blumin awful to the extent that it makes the family car sick.

They also wear out really quickly and cost a lot more to replace. They are extremely difficult to balance correctly meaning there is always minor wheel / steering vibration at motorway speeds.

I drive motorway, A / B and un classified roads almost every day. The only road they are adequate on is motorway. The rest they are a total waste of time and take motoring, ride, handling and comfort back 20 years.

I won't buy another BMW while they continue to fit run-flat's.

I also have a 320d with RFTs (Now Michelin, previous 2 sets Conti). They are not as compliant as regular tyres but I think that you are laying it on a bit thick. I have never had a complaint from anyone about the ride.

I also have a Z4 with them. Now that, on bumpy roads, is a bit bouncy but its only done a couple of K and it's getting better all the time, so I reckon that is more to do with springs and dampers, not the tyres.

Finally, your problem with balancing them is I fear, nothing to do with the tyres. I have fitted and balanced both replacement sets on my 320 myself and they are perfectly balanced. I would suggest someone wasn't paying attention when you had yours done!

Having said all that, I would prefer the ride I guess of non RFTs, but not that much to bother changing, especially when my wife and kids use the cars.

Edited by DSM2 on Tuesday 8th July 23:33

[gizlaroc]

DSM2 said:

I also have a 320d with RFTs (Now Michelin, previous 2 sets Conti). They are not as compliant as regular tyres but I think that you are laying it on a bit thick.

have you tried your car with non run flats?

I hear this from everyone and as soon as they do they realise what it is meant to feel like.

[rich_vw]

Well by the looks of this its stick with the run flats until a change is required and try none, as noted by a few of you it seems to be down to the individual and the roads your on.... I will be mainly dual carriage and motor ways with the odd weekend hoon for myself so hopefully the run flats wont be bad, only time will tell I guess.

[DSM2]

gizlaroc said:

DSM2 said:

I also have a 320d with RFTs (Now Michelin, previous 2 sets Conti). They are not as compliant as regular tyres but I think that you are laying it on a bit thick.

have you tried your car with non run flats?

I hear this from everyone and as soon as they do they realise what it is meant to feel like.

Not mine, no, but I have driven a 3 series with regular tyres and the ride was much softer but I didn't have time to make a full comparison. As I have said, I don't find the RFTs bad enough to want to change. If I have the car when the current set needs replacement maybe I will try a set of non RFTs. Of course, then I need to carry a spare and buy a jack etc.

I am in a privileged position in that I am not too concerned about tyre life, but at about 23K per set, the RFTs compare OK with previous cars I have had. the last two daily drivers were a chipped Golf 150 and a Mitsubishi VR4 (now that did eat tyres!).

I guess that neither of those had a particularly soft ride either, so again the RFTs don't seem so bad to me. These days, if I'm not in a car with RFTs, I'm riding on 305/30s and 235/35s, not particularly cossetting!!

Another small point: what pressure do you put in non RFTs? As far as I know BMW don't have a recommendation and I would guess they should be significantly higher than RFTs, having so much softer sidewalls.

[gizlaroc]

Other way round, run flat actually run at much higher pressures than regular tyres, so you need 38psi in an 18" run flat you only need around 34psi in the non run flat.

I had been running round on 245/40/18 and 265/40/18 tyres for a couple of days, instead of the 225/40 and 255/35 that come on the car as standard and the same as Alpina use, and it transforms the car, more bite in corners and the ride becomes sublime!!
Just with the aggressive offset of the M3 wheels the rears did rub when fully loaded going ove rspeed bumps. I nearly put the 335XD springs on the car to stop this, which are around 15mm higher and stiffer (which is also what Alpina use) but in the end went back to the correct profiles as it was easier.

But just shows you why the M division refuses to use run flats. The latest generation from Michelin using the Pilot Sport 2 pattern and with slightly softer side walls are getting alot better, but the difference is still quite amazing, but I think they have got to the point where you are not thinking these have got to go.

[ScottL]

I swapped the Michelin Pilot Sport run flats on my 330d Touring for new Pirelli P Zero (non run flats).



What a difference. The fidgety, crashy ride is gone. Grip levels are much better. Highly recommended.

[welwynnick]

I think run-flats only make a difference to the ride where TYRES themselves make a difference, and that is where the bumps are short, and the tyre absorbs some of the shock. It's a question of frequency. Longer bumps are ignored by tyres, and the suspension absorbs them. If you're driving on a bumpy but unbroken road, RFTs may be OK.

But where the surface is broken with damage and repairs, you'll feel like you're driving on solid lumps of rubber, rather than a high-tech descendant of Mr Dunlops original brillinat invention, which relied on the AIR in the tyre to support the weight, rather than the RUBBER in the tyre.

Autocar complained bitterly about the ride on run-flats, and I find they are usually on the money.

Nick

[topaz]

I have a 335i coupe with the 19" star spoke alloys. The RFT are 30 and 35 profile and the ride is absolutely shoking. I thought I could cope with it during the test drive but on my local roads it is truly awful. My fillings ae all loose and I've hit my head on the headliner due to ruts in the road. Only done 6000 miles but will either do a straight swap for normal one or get some 18" rims with normal tyres.

[TheCaseAce]

Continental ContiSportContact SSR's here on an E91 325i.

Ride is firm, but not jiggly or crashy. Nothing to bother me at all, or prevent me buying another 3.

Would love to put a set of non-RFT's to see what difference it would make, but at £100+ per corner it's an expensive experiment.