Tyre brand advice please

Have decided against this after much research over past week.

The main reason is that I spoke to two people on the phone I know who also own Z4 cars. One changed to non run-flat tyres and said the handing is a bit questionable after doing this, he is a professional driver.

Fact is, the Z4's that come with run-flats have softer suspension; something has to give. So by putting non run-flat tyres, everything is a little bouncy and handing becomes a trifle wayward.

You can specify a non run-flat Z4 when ordering a new one. BMW then use different suspension and settings to reflect this fact.

Realistically, you should only change to non run-flats if you are going to change the entire suspension system and have the car sorted in every other way so it maintains correct driving characteristics.

If you just want to ponder around with a soft ride it is fine, but if you want to grab it by the scruff and point it and have fun, forget it; you'll lose handling and more.

So I'm going to accept the somewhat hard ride and stick with run-flats.

I want to test drive the new shape Z4 as the iDrive system has suspension settings from what I can gather.

As ever, thanks for all the input, without which, I would not have been able to come to my conclusion.

Oh, it wasn't just BMW who told me this, a few independent sources also informed me of the scientifics.
 
Are you talking about the new Z4 or the original?

I can believe it for the new one, but the originals run flats are far too hard and make it a pain on rutted roads.

There's a reason the M division won't use runflats :wink:
 
If that was the case, then why are there no suspension changes when the dealer will sell you 19" wheels (with ~35 profile tyres) instead of your standard 17" wheels (with ~45 profile tyres).

Also, if it was that sensitive, you'd have to get the suspension changed every time you changed tyre brands or as they heated up and increased pressure.

If you're planning on getting the EDC option, then make sure any faults are rectified within warranty or you'll be facing a £750/corner bill, compared to the standard £200/corner - and they're heavier.

BTW, if there's different suspension settings for all these different tyres (a Michelin sidewall is not the same a Pirelli, etc.) then why are there no part numbers for 'non-runflat' springs/shocks? (there are part numbers for standard, M-Sport, and EDC).
 
Well like Finisterre said, I'd rather listen to BMW, than 'some bloke off the web', respectfully of course.

If you have already put none run-flats on, go ahead and justify it any way you like, I'd expect nothing less.

For me, I've called three BMW dealers and spoke to technicians at all of them, they all say you are playing a risky game doing that.

I don't deny that different brand run-flats are marginally different. But one brand to another is still comparing apples with apples. Comparing run flat to non run flat is comparing apples with lemons; different thing altogether.

Herminator, all BMW dealers told me this about my E85 older Z4, but they also said it is the same case with new ones. Cars designed for run-flats, HAVE to have run-flats; end of.

mmm-five, different wheel sizes is not the same thing at all, it is not apples for apples is it. If the wheel size changes, but they are still run flat tyres, everything is ok.
 
Look, sorry about the 'dick' comment. But I just could not see the point in that futile sarcastic comment. It is obvious I don't know my stuff, hence my asking the question on here. But after seeking 'professional' advice form several BMW dealers, the consensus is, forget it, you are playing Russian Roulette with your cars handling.

At the end of the day, each to their own. I'm going to test drive the new 3.5 and see how it is in comparison.
 
BMW dealers are obliged to follow the party line.

Why not borrow a set of wheels with normal tyres on them once you have a car to muck about with?

PS dick is fair, I was mocking you.
 
I know what you mean, Finisteer, about BMW's party line etc. But Performance Tyres in Huntingdon said I was mad even considering it, unless I was going to change the suspension too.

Borrowing a set of wheels would be impossible, wouldn't know where to start. I think I'd have more look finding somebody with a 3 litre Z4 with non run-flats who might be happy to take me out in there car for 15 minutes. As long as I'm not crass by calling them a dick first ;)
 
gannet said:
Nigel-Z4 said:
I think all run-flats are like bricks regardless of brand, model; it is the nature of the wall of the tyre.

It is interesting that the Potenza RE050A none run-flat version is no longer available; they discontinued it.
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and how many brands have you based that on??

OEM Bridgestone's were admittedly shite and dangerous, which is why I switched to Michelin's PS2 ZP tyres - difference was night and day, like riding on normal tyres.

not many people on here believe me though - hey ho :evil:
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I do mon ami .............I have just ordered a set ,from my Dealer , who virtually matches Micheldever tyres in price

I am really hoping you are right :D
 
And here's me reading it as you mocking me and backing up Nige :oops:
The internet is wide open to interpretation. As is the info dealers give out. They told me the wheels wouldn't take non-runflats. A tyre fitter explained it as runflats won't fit an ordinary rim but regular tyres on a runflat rim was fine.

All I know is there's a huge amount of experience on here with using regular tyres on the original Z4 and it all seems to be positive.

Luckily with my car I don't have the decision to make 8)
 
I'm almost inclined to take gannets advice and look at replacing the rear two (which are getting close to legal limit) with the Michelin PS2 ZP run-flats. Well, PS3 anyway as the PS2 have just been discontinued, PS3 is the replacement.

My front tyres are Goodyear and a Bridgestone, and are like new. So in a thousand miles, I'll replace my worn rear ones with the PS3 ZP run-flats and see if that half helps, then when the front need it in 20,000 I'll match all for with two more PS3 ZP's
 
Herm - sorry about that-- :)
It would be nice to have an M but as it is we have a space saver in the boot and the difference in comfort makes it well worth while.
 
BMW are not allowed to recommend or fit anything other than OE kit. Full stop. Owner at my local tyre outlet runs his BMW on non RFTs. Loads of users on here report their car being positively transformed by a move away from the OE Bridgstone RFTs, there is no issue with fitting non RFTs. I switched to Falkens and agree that the side wall gives a little more, so turn in is a little less crisp, but it don't bounce all over the place or tramline like a bitch any more. Fair swap in my book.

If I could justify the cost I would go for the Michelin RFTs, if not the Falkens 452 suit the car very well, the Goodyear Eagle F1A and the Vred' are well liked by many Z4 owners and I'd be happy with either, whatever you choose I'd get the original Bridgstones off. Let us know how you get on :thumbsup:
 
Good points Ewazix. I only considered none run-flats as my rear two are nearly at the end of their life. But the front two are as new. And yes, I was thinking price as two run-flats are £600 and four non are £500.

The tramlining is not a big deal for me, I have got used to it. But the bouncing, or should I say, bumping, around all the bloody time does my head in. Whenever I see those 'count down' lines in the road coming up to a roundabout I have on occasion said out loud to myself 'hold onto your knickers' in preparation for having vertebrae dislodged in my spine.

Are the Michelin PS2 Z2 run-flats REALLY just as comfortable as something like the Falken's?
 
I'm buying a set of Goodyear F1 Assymetric 2s for my Z4. Previously I had these fitted to my Abarth and they were much quieter than the Pirelli P Zeros. Great in the wet and dry too. Worked really well on track.

They also have a protective lip which helps prevent kerbing.
 
Nigel-Z4 said:
Finisterre, I don't know my stuff, but, erm, let me think, erm. THREE BMW DEALERS DO!!! dick.
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I was chatting to a BMW service manager the other day and mentioned that I am thinking about fitting non run-flats to my Z4. He agreed that it is a reasonable idea but that I should check that it is acceptable to my insurance company.

3-1 then.

Oh well there's always Goodyear run flats.
 
Nigel-Z4 said:
Have decided against this after much research over past week.

The main reason is that I spoke to two people on the phone I know who also own Z4 cars. One changed to non run-flat tyres and said the handing is a bit questionable after doing this, he is a professional driver.

Fact is, the Z4's that come with run-flats have softer suspension; something has to give. So by putting non run-flat tyres, everything is a little bouncy and handing becomes a trifle wayward.

You can specify a non run-flat Z4 when ordering a new one. BMW then use different suspension and settings to reflect this fact.

Realistically, you should only change to non run-flats if you are going to change the entire suspension system and have the car sorted in every other way so it maintains correct driving characteristics.

If you just want to ponder around with a soft ride it is fine, but if you want to grab it by the scruff and point it and have fun, forget it; you'll lose handling and more.

So I'm going to accept the somewhat hard ride and stick with run-flats.

I want to test drive the new shape Z4 as the iDrive system has suspension settings from what I can gather.

As ever, thanks for all the input, without which, I would not have been able to come to my conclusion.

Oh, it wasn't just BMW who told me this, a few independent sources also informed me of the scientifics.
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This is an interesting discussion and the above are interesting comments. I would be interested to hear the Scientifics mentioned by the independent sources? The independent tyre supplier I used today have changed many run flats to non run flats as many BMW owners felt the run flats were terrible!

Today I took my car in to have all the run flats (Bridgestone RE050A) with non run flats (Kumho Ecsta KU39's). The run flats were all still legal with plenty of tread left, but I simply could not live with that ride any more. In my opinion the Bridgestone run flat tyres were terrible. They were stupidly hard and uncomfortable. That in turn made the car feel very jumpy and skittish over rough surfaces leaving you with little confidence at times. I can't comment on other run flats as I have never used them. After the last set of run flats I never will...

First of all it is interesting that some "experts" I spoke to about changing from run flats to non run flats told me that a run flat rim could not accommodate a non run flat tyre. That is clearly nonsense. Obviously you have been told by 3 BMW dealerships that the suspension is set up for run flat tyres. Now this is probably true to a certain extent, but to suggest that putting non run flat tyres on the car will somehow make the handling dangerous is really a load of nonsense as well. I would be asking these "experts" exactly why putting a non run flat tyre on a Z4 is "playing a risky game". If that were true, there would probably not be two suspension options available on a Z4 (sport and standard). One of these setups is harder than the other, yet both setups were sold by BMW with run flat tyres. Not to mention the different profile tyres provided on different size wheels. The ride characteristic of a 16" alloy with a higher profile is very different indeed to the characteristic of an 18" alloy wheel with a lower profile tyre, yet again BMW sold the Z4 from the factory with different size alloys on the same suspension setup. This would not be possible if the suspension was sensitive enough to be perfect for a run flat tyre yet risky on a non run flat. I would suggest that the difference between an 18" run flat tyre and an 18" non run flat tyre not hugely different to a higher profile 16" run flat tyre against a lower profile 18" run flat tyre.

I can safely say that putting non run flats on my Z4 is one of the best things I have done to my car. The ride has been transformed, there is no more banging and crashing around over bumps and surface imperfections and everything feels much more civilised. There is no more skittishness I experienced on the run flats. The car feels much more planted and stable on the road and the tyres are much quieter. I can't think of a downside at the moment (I have purchased a BMW mobility kit to combat punctures); in fact I think my car is actually safer on the non run flats due to the increased stability. If you read around in this forum you will find that many, many Z4 owners have also got rid of their run flats and commented on the improvements felt.

BMW will always say that you have to use run flats as that is the official line. I understand why you may want to continue using run flats because of the advice you have received. However to dismiss non run flats when so many owners are using them in the real world with no ill effects at all would be a shame as you really are missing out on a much improved driving experience...
 
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