Your thoughts please

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pugsey

Member
Email from BMW ref RFT

The decision to remove the run-flat tyres from your vehicle and replace them with standard tyres needs to be considered carefully. The suspension, steering, chassis and tyres have all been designed to work with the run flat concept. Consequently, unusual handling or steering characteristics maybe experienced if using standard tyres and of course there is a considerable reduction in safety.



We would not be able to state that fitting standard tyres is wholly acceptable as the vehicle was given type approval to be imported into this country with run-flat tyres fitted. By fitting standard tyres it changes the originality of the type approval of the car by reducing the safety levels offered by run-flat tyres. Although technically this can be done it is entirely at the owner’s discretion to change from run-flat tyres to standard tyres. Before finally making your decision to change your tyres to standard ones, I would urge you to consider the considerable benefits that run flat tyres offer above standard tyres. Also, you should verify with your car insurance company that they agree to you fitting standard tyres. Should the standard tyre blow out and result in you having an accident, the tyres would be checked by the insurance company and if found to be standard tyres, they could decline your claim.

With the latest generation of run-flat tyres now being
 
That was what I was told yesterday by the guy in the local workshop - although th concern was almost entirely what would happen with a high speed blowout. I relayed this to my insurance who regarded it as a downgrade and no additional charge :thumbsup:

I’d be interested to see what they have to say about the tyres on the M variant which puts a great load on the tyres, is faster and yet has standard tyres.

There is a change in the way the car handles, or at least the feel (IMO!) – I’m looking at stiffening the suspension / anti-roll bars to compensation. But on the whole the car is less volatile over un-even road surfaces and I personally feel safer.

Non-Bridgestone RFTs could be an option is BMW's response concerns you.
 
I don't think BMW could say anything else than what they have commented here. They remain vague, reference how the car was type approved with RFT's and point to the suspension being RFT designed, add a reference to insurance and possible claims issus, etc. to avoid any liability.

If you asked them about changing springs, shocks, and so on you'd get the same reply and with regards to ///M's they'd say they were designed for non RFT and so type approved.

Good that they do confirm that 'technically this can be done'.
 
All very valid I suppose, but as PawnSacrifice says what about the M... spose they would argue that its suspension is different and therefore cant take the RFT....

I switched to Michelin PS2 ZP (RFT) 18 months ago and cant recommend them highly enough. Id burnt through new Bridgestone rears in the same time (18months) but Ive now still got 4mm left on the back, 6 on the front :D Ride and handling much improved :thumbsup:
 
I just cant believe that chassis would be designed around the tyres....maybe BMW have invested loads in RFT and everyone is switching to non RFT
 
cj10jeeper said:
I don't think BMW could say anything else than what they have commented here. They remain vague, reference how the car was type approved with RFT's and point to the suspension being RFT designed, add a reference to insurance and possible claims issus, etc. to avoid any liability.

If you asked them about changing springs, shocks, and so on you'd get the same reply and with regards to ///M's they'd say they were designed for non RFT and so type approved.

Good that they do confirm that 'technically this can be done'.
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Absolutely... my comment about the M variant was in regards to this issue of safety with a high speed blowout, which is, to my understanding, why BMW chose the RFT route originally, if it is so important why not design the M car around them?

They must get this a lot because it is almost exactly what I was told on the phone yesterday by a dealer in Reading... where there's blame and all that! How much cheaper / better / easier would our lives be without those people!

As an aside, if there were run flats that I had experience of personally, that ran as well as normal tyres, I'd buy them!
 
pugsey said:
I just cant believe that chassis would be designed around the tyres....maybe BMW have invested loads in RFT and everyone is switching to non RFT
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It's been discussed elsewhere before but the fact is that cars are moving to RFT's due to several factors primarily around packaging (getting all the required components into a given car size) and fuel consumption through reduced weight. Imagine finding space to keep a spare without changing body shape or losing all the boot.

In 10 to 15 years I doubt there will be a car on the road not on RFT's, but for now the technology is only just getting right and on the Z4 it was perhaps a step too far in 2002 on the first gen Bridgestones.
 
Ultimately your decision - One I faced when I switched RFT brand. just preferred not to have to find an alternative, pump tyre seal etc. Remember thatmore modern run flat tyres were developed after the initial Z4 and BMW themselves admit that the Z4 was a 'run flat pioneer'. I seriously couldnt believe the difference between the bridgestone and michelin variants. It is so profound that I noticed the better ride just driving off the tyre places forecourt. Mrs Gannet also noticed just backing off the drive.

Was a big leap of faith though.
 
If you're going to stick with run flats why not try the Michelins Gannet's running? I'm starting to think there must be something to it as he's been a big advocate in the face of a lot of adversity! Things can't get any worse.

Just don't do anything that's going to play on your mind an lesson any enjoyment... have you holding back when you should be :driving:

If you can hold off a little while why not try and get down to a meet and get a ride in someone else's car? If you're passing Reading I'll happily take you for a run out in mine.

EDIT: gannet beat me to it!
 
just got quoted £365 fitted Falkens 452.... think i will go for them and hope the ride although different will be better
 
pugsey said:
Well i work in Bracknell so not a million miles away, so you made the change to non RFT then ?
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Yep - Goodyear Eagle F1s and they're great! Good deal from Elite just around the corner too. Turn in does feel a little soft although that may be 3.5 years on RFTs! Have revived an old thread looking at replacing the anti roll bars. But even without the suspension change I wouldn't go back. Sure many others would say the same!

Otherwise why not get down to...
http://www.z4-forum.com/forum/viewtopic.php?f=14&t=14716
I'm in Bristol Saturday night so can't make it otherwise would definitely be there! Assuming they let me "in". I went to my first forum meet last weekend (120 miles away) - :thumbsup:
 
Changing from RFT's to normal tyres may make an improvement in the handling, but I don't think the RFT's are wholly to blame! I think it's just a "quick fix" changing them (bit like placing a soft cushion on a hard seat when the problem is really the seat design being too hard!).

After driving my new Z4 for a while now I would say they got the handling slightly wrong for the first gen Z4's from the start! The difference in the quality of the drive on normal roads when driving "with pace" in the new Z4 is very noticeable! Not to say the 1st gen's don't handle, they do, but they take a lot more concentration to do so!
 
ha ha not stalking you or anything but im down Bristol way over the weekend lol

Bracknell tyres is where im potentially getting them done...there ordering them in so will have 2nite to consider the options...
 
pugsey said:
just got quoted £365 fitted Falkens 452.... think i will go for them and hope the ride although different will be better
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If you haven't already you may want to let Bracknell Tyres know they're replacing run flats... it's not a problem but some outlets think it is and won't touch them! Might just save a wasted trip.
 
yeah i mentioned it when i phoned up they said they done a lot of these...kwick fit wanted a email from BMW to swap them...both branches were very helpful tho
 
now they are talking rubbish....

As all Z4’s were produced with run-flat tyres BMW do not list any alternative suspension parts. The cost of replacement parts such as shock absorbers, roll bars, springs and possibly other components would be far in excess of the slightly higher price of a set of run flat tyres compared to standard tyres
 
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