The great run flat tyre debate.

[Monty Python]

Swervin_Mervin said:

In my case of moving from the same tyre in RFT to non-RFT, I'm talking about wrestling the steering wheel one day just to keep it in a straight line, and wincing over anything resembling a bump, to practically being able to drive no hands in a straight line and thinking "what bump?".

It is that marked a difference.

Herein lies the problem - I've never experiences the kind of "wrestling" you have - and that's in 8 years of driving on a mix of 18/19" runflats of various types.

[smashy]

All i can says from 2008 to 2014 and shed loads of miles every runflat i had was awful 3 years of michelin ps3 normal excellant....and now after tons of online reviewing and forum hunting goodyear eagle f1 asymetric 3 Runflats very very good.So good I wouldnt change.The only pain going forward if you buy a new car you cannot specify tyre make so it will probably be horrible contis or bridgestones again and I really dont fancy that

Edited by smashy on Friday 19th January 19:12

[anonymous-user]

Monty Python said:

Swervin_Mervin said:

In my case of moving from the same tyre in RFT to non-RFT, I'm talking about wrestling the steering wheel one day just to keep it in a straight line, and wincing over anything resembling a bump, to practically being able to drive no hands in a straight line and thinking "what bump?".

It is that marked a difference.

Herein lies the problem - I've never experiences the kind of "wrestling" you have - and that's in 8 years of driving on a mix of 18/19" runflats of various types.

Nor me. Even when I’ve been made to drive a loaner 1 series.

[Mr Tidy]

Monty Python said:

I'm surprised nobody has produced any empirical data on the subject - personal views don't really help as everyone has different tolerances towards what sort of ride is acceptable.

I think the problem is it isn't easily measurable, it's all just a matter of opinion. Saying that though it is useful to read how other people who have had them rate what they have used.

[Mr Tidy]

I have to say I had a 123d used exclusively on Pirelli RFTs for over 6 years. It was on it's 4th set when I sold it.

It was an SE Dynamic, so although it had the M-Sport suspension it had pretty modest 205/50 x 17 tyres.

It certainly didn't have a wafty ride, but was never crashy over the 81+K miles I had it.

But once the tyres got down to 4mm tread or so it did tend to tramline, and that got much worse if the pressures had started to drop.

Then in 2014 I bought a Z4 Coupe with M-Sport suspension and 225/40 x 18 front and 255/ x 18 Bridgestone RFTs, and it just didn't seem to want to go in a straight line! I had the front "lollipop" bushes replaced, but it wasn't much better.

I stupidly sold it in 2016, and within a week had bought another Z4 Coupe with the same suspension set-up and tyres, and it drives better than the previous one and it does tramline a bit - especially on the inside lane of motorways where you can see the HGV ruts!

Both suffer from a crashy ride, especially if I hit a pothole, so I am looking forward to putting my non-RFT winter Falkens (same sizes) onto my current one to see how it feels.

[Dino D]

Bridgestone DriveGuard have good reviews and here is a test back up back between Bridgestones on the same car: http://www.tyrereviews.co.uk/Article/Bridgestone-D...

I’m giving them a go on a Smax ford (it has no spare but does not have runflats as standard - would prefer the convenience of a runflat on a family bus). It’s has big sidewalks so hopefully no real downside to the ride.

[Wills2]

If it's a an f31 335d then it's a soft roly-poly pudding of car I doubt changing the tyres will help, surprised you think it's harsh.

[Mr Tidy]

Dino D said:

I’m giving them a go on a Smax ford (it has no spare but does not have runflats as standard - would prefer the convenience of a runflat on a family bus). It’s has big sidewalks so hopefully no real downside to the ride.

Just a thought, but does the car have any Tyre Pressure Monitoring System? If not, you really don't want run-flats on it as you'll never know if you have a puncture.

[Dino D]

Mr Tidy said:

Dino D said:

I’m giving them a go on a Smax ford (it has no spare but does not have runflats as standard - would prefer the convenience of a runflat on a family bus). It’s has big sidewalks so hopefully no real downside to the ride.

Just a thought, but does the car have any Tyre Pressure Monitoring System? If not, you really don't want run-flats on it as you'll never know if you have a puncture.

Yes it does, I think all cars after a certain year did. This tyre is for cars that didn’t have RFT but they say you must have TPMS to be able to fit (normal rims are fine they say).
Think it’s an MOT issue too if you don’t have TPMS abut have RFT.

[keepoffthemarbles]

Wills2 said:

If it's a an f31 335d then it's a soft roly-poly pudding of car I doubt changing the tyres will help, surprised you think it's harsh.

Thanks Wills. I wondered how long it would be before someone bought it back to a 335d bashing. To put it in perspective, this is a medium sized diesel estate car which I use to ferry my family, dog and our golf clubs around and in my opinion it does it very well. But I don't like the tyres - specifically the ride comfort they provide.

Is it soft? Not soft enough in my opinion hence my desire to change the tyres.
Is it roly-poly? Probably if you drive it that way, but I don't because the dog doesn't like it and my golf balls roll around.
Is it a pudding of a car? No, a pudding is something you eat.
Will changing the tyres help? Yes it sounds like it will help solve some of the points I'm complaining about. At no time did I ask if changing the tyres will turn it into a racing car.

I appreciate you have an opinion, but it'll probably be more useful on the MaxPower forum.

Edited by keepoffthemarbles on Tuesday 23 January 13:53

[nbetts]

keepoffthemarbles said:

Thanks Wills. I wondered how long it would be before someone bought it back to a 335d bashing. To put it in perspective, this is a medium sized diesel estate car which I use to ferry my family, dog and our golf clubs around and in my opinion it does it very well. But I don't like the tyres - specifically the ride comfort they provide.

Is it soft? Not soft enough in my opinion hence my desire to change the tyres.
Is it roly-poly? Probably if you drive it that way, but I don't because the dog doesn't like it and my golf balls roll around.
Is it a pudding of a car? No, a pudding is something you eat.
Will changing the tyres help? Yes it sounds like it will help solve some of the points I'm complaining about. At no time did I ask if changing the tyres will turn it into a racing car.

I appreciate you have an opinion, but it'll probably be more useful on the MaxPower forum.

Edited by keepoffthemarbles on Tuesday 23 January 13:53

Not that I need to defend Wills2 and his remarks but what is useful to note is that the 335D in both M-Sport and SE variants both ride on the more comfortable and better suited to the car SE Dampers and springs.

In my experience of run-flats, they do take away some the comfort - which is noticeably lacking if you go over a wash-board like road surface - the run-flats really struggle with that sort of surface.

I had a M135i with and without run-flats and the non run flat tyres were premium Michelin - the car was definitely more composed on normal tyres but I eventually put run-flats back on when the others were worn just for the utility of not having to stop at the side of the M25 to attend to a flat tyre.

Worth a all the money in the world when you have been buzzed by a lorry on the hard-shoulder.

[FurtiveFreddy]

Had runflats on my 335i when I bought it in September '15 but soon swapped them for Mich. Pilot Sports.

Much better ride and tons more traction when cold and damp.
Bought the BMW gunk&pump kit off ebay but haven't had a puncture (yet) so no hassle there.

I think it depends on the sort of journeys you're doing and whether ultimate handling/ride/comfort is important to you. If I was doing lots of long journeys away from home, maybe RFTs would make more sense but the one time I have had a puncture with a RFT, we were in the Lake District a long way from home, on a Saturday afternoon and were very lucky to find a fitter near to where we were still open and who had a replacement in stock.

We could easily have been stuck there for a day or had to have the car recovered for the sake of that puncture.

After driving the 335 for a while I now realise how average the whole factory suspension setup is, even on non-RFTs, so I'm soon going to get a Birds package on it and this is what they say on their website about tyres:

Birds said:

A note about tyres. All BMW cars except the M-Power cars are equipped with Run-on-flat tyres from the factory. We cannot stress how important it is to rid yourself of these performance sapping devices. In our opinion, the arguments proposed by BMW for these tyres is totally misjudged, and we know of no customer who regrets installing conventional tyres.

[keepoffthemarbles]

Yep I'm pretty well up on the Msport supplied with SE springs. I think it applies to all xDrive cars these days.

A friend of mine swapped to ACS springs on his 335d and he says it made a big difference to the 'ride & handling' and certainly the car looked different sitting a little lower. From the passenger seat it sounded just as crashy and bangy as mine does as he still had the RFTs.

As I said, this car isn't used for the type of driving that warrants lower better handling characteristics. Having said that, I'd be interested to hear from anyone who swapped to non RFTs, noticed a ride improvement and then swapped springs. Did you notice more ride improvements?

No offence was intended towards Wills by the way.

[msej449]

'A note about tyres. All BMW cars except the M-Power cars are equipped with Run-on-flat tyres from the factory. We cannot stress how important it is to rid yourself of these performance sapping devices. In our opinion, the arguments proposed by BMW for these tyres is totally misjudged, and we know of no customer who regrets installing conventional tyres.'

Until they are killed in a high-speed tyre blow-out.

The proposition from BMW is that runflats are much safer in a deflation at speed than conventional tyres. The quote clearly states that BMW are wrong. On what evidence? The statement also claims runflats 'degrade performance' - really? Again, on what evidence and in what sense do they inhibit performance?

I'm sure they make fine LSDs but it's completely irresponsible to recommend people do stuff to improve handling at the cost of safety. It invites a massive liability if someone were to take their advice and have an accident that could have been prevented by runflats. I'm cool with people being given a balanced choice between improving handling but degrading safety, and then making a choice, but this speaks of the benefits as if there were no downsides.

And I'm still not convinced, when I can only find a very few instances of owners changing to exactly the same non-runflat as runflat tyre. Almost all the reports I've read describe moving from one brand to another that's completely different. In which case it's impossible to know how much of the improvement is due to brand, and how much to being non-runflat.

Edited by msej449 on Tuesday 23 January 16:52

[Swervin_Mervin]

msej449 said:

'A note about tyres. All BMW cars except the M-Power cars are equipped with Run-on-flat tyres from the factory. We cannot stress how important it is to rid yourself of these performance sapping devices. In our opinion, the arguments proposed by BMW for these tyres is totally misjudged, and we know of no customer who regrets installing conventional tyres.'

Until they are killed in a high-speed tyre blow-out.

The proposition from BMW is that runflats are much safer in a deflation at speed than conventional tyres. The quote clearly states that BMW are wrong. On what evidence?

The statement also claims runflats 'degrade performance' - really? Again, on what evidence and in what sense do they inhibit performance?

Sorry, but I'm sceptical. Not only is it contrary to the stated claims of BMW in regard to a technical feature of their cars, but it invites a massive liability if someone were to take their advice and have an accident that could have been prevented by runflats.

Edited by msej449 on Tuesday 23 January 16:38

Because this happens ALL THE TIME.

Other manufacturers must be right C-units then as only a few manufacturers fit RFTs from new

[anonymous-user]

Swervin_Mervin said:

msej449 said:

'A note about tyres. All BMW cars except the M-Power cars are equipped with Run-on-flat tyres from the factory. We cannot stress how important it is to rid yourself of these performance sapping devices. In our opinion, the arguments proposed by BMW for these tyres is totally misjudged, and we know of no customer who regrets installing conventional tyres.'

Until they are killed in a high-speed tyre blow-out.

The proposition from BMW is that runflats are much safer in a deflation at speed than conventional tyres. The quote clearly states that BMW are wrong. On what evidence?

The statement also claims runflats 'degrade performance' - really? Again, on what evidence and in what sense do they inhibit performance?

Sorry, but I'm sceptical. Not only is it contrary to the stated claims of BMW in regard to a technical feature of their cars, but it invites a massive liability if someone were to take their advice and have an accident that could have been prevented by runflats.

Edited by anonymous-user on Tuesday 23 January 16:38

Because this happens ALL THE TIME.

Other manufacturers must be right C-units then as only a few manufacturers fit RFTs from new

Tyre failure is quite significant in accident causes. Do a little research, it’s not hard to find the information.

Why do you think TPMS are mandatory? A direct result of fatalities caused by tyres that failed catastrophically. They weren’t runflats though.

[msej449]

Umm, well, it's hard to be sure with any degree of objective certainty, based on real data. I'm sure that many people have got better perceived handling when switching from one brand of runflat to another brand of non-runflat. But as I said, what does that prove, other than that the replacement tyres is better? I do believe the claim that runflats are good if you suffer a blow-out at speed - I've seen enough videos, and I've personally benefited from them in these circumstances. So to persuade me to switch, I need something a bit more objective and evidence-based than I've seen so far.

My criticism of Birds is that they are stating that the BMW claim of runflats being safer is wrong. But they offer no evidence for this. All they talk about is performance benefits. But BMW make no claims for better performance. Just greater safety. Of which Birds say nothing other than that BMW is wrong. This wont' convince me to switch.

[FurtiveFreddy]

msej449 said:

My criticism of Birds is that they are stating that the BMW claim of runflats being safer is wrong. But they offer no evidence for this. All they talk about is performance benefits. But BMW make no claims for better performance. Just greater safety. Of which Birds say nothing other than that BMW is wrong. This wont' convince me to switch.

Where are you finding BMW saying that the ONLY reason to have runflats is safety? This is actually what BMW say:

"With BMW approved Star Marked run-flat tyres you can keep driving even when you have a puncture. The Tyre Pressure Monitoring device that is installed on your BMW lets you know if your car tyres are punctured, and instead of stopping allows you to drive for up to 50 miles at 50mph. Never miss an appointment, don’t worry about a spare wheel and reduce the risk of an accident with sudden loss of tyre pressure."

So, the first point they make is about convenience. BMW recommend and fit non runflats on some models, so if they were particularly concerned with people being killed because of blow-outs, why would they fit non RFTs to their higher performance models which will be driven faster if anything?

In fact, the reason blow-outs often lead to injury is because drivers don't know how to react to the situation and panic steer/brake. The same way they behave when there's snow, ice, standing water, traffic suddenly stopping in front of them and all sorts of other hazards. I've had exactly one high speed blowout in >35 years of driving (much of it at high speed) and I stopped perfectly safely without the help of RFTs.

It's a free country and if you feel safer with them then use them, but please don't scaremonger that non-RFTs are significantly more dangerous, because that's bks.

[msej449]

FurtiveFreddy said:

It's a free country and if you feel safer with them then use them, but please don't scaremonger that non-RFTs are significantly more dangerous, because that's bks.

Non-runflats are significantly more dangerous than runflats when suddenly deflating at speed. Look at the videos e.g.

https://www.youtube.com/watch?v=4FOIubWv6Cs

If you used your brain rather than shouting abuse, you might posit that the probability of this happening is so low that it's not worth any compromise in handling, which is a reasonable position.

I don't know why I'm making your argument for you - perhaps I should just swear and it would be more convincing?

Edited by msej449 on Tuesday 23 January 19:12

[Prinny]

My snip...

keepoffthemarbles said:

To put it in perspective, this is a medium sized diesel estate car which I use to ferry my family, dog and our golf clubs around and in my opinion it does it very well.

Edited by keepoffthemarbles on Tuesday 23 January 13:53

Sod the debate about the tyres, got any video of the dog playing golf?

My ultimate take on tyres: the M-Division has never specified run-flat tyres on an M-car. Therefore they must believe run-flats are not the best performance option.

How applicable that statement is to you depends on your assessment of the place the car sits on the performance<>family wagon continuum. I appreciate there’s further detail than just that analogy, but it’s the crux of the matter, IMO.

Edit - looks like everyone else is mentioning the M-thing. Didn’t read to the end before posting. Apologies to all.

Still want to know about the dog though!

Edited by Prinny on Tuesday 23 January 19:26