[Jonny Fortnight]

Hi guys & gals,

I've just purchased a new car which has run flat tyres. I was wondering if anyone knew much about these. I understand that you can drive on them with a puncture but what I would like to know is, how much will they effect the performance and economy of my car?

Any help and advice would be much appreciated.

[Meaty Weaty]

Performance and economy shouldn't be affected too much because you really shouldn't drive on them for longer than absolutely necessary!!! They're a temporary measure, not a long term alternative to getting off your backside and changing the tyre! Doh!

[Meaty Weaty]

But seriously :D check out http://www.etyres.co.uk/run-flat-tyres for more information on them. Quite technical, but plenty to learn about - especailly that these tyres aren't indestructible, and must be replaced.

[Jonny Fortnight]

Thanks for that comment but I seem to have been misunderstood on this one.

What I meant to ask was, whilst fully inflated, can they affect performance and economy?

[Meaty Weaty]

Whoops

the article above just states that fuel and performance are improved by the reduced weight (4 tyres instead of 5 + no need to carry a jack etc), all the benefits seem to be in terms of safety.

Worth noting that the cost of replacing a damaged RFT is significantly more than a repairing a normal tyre. This is causing some people to replace RFT's with normal tyres. Others think that handling is affected adversley by RFTs (when running normally). I've no personal experience of this. Anyone else?

[Jonny Fortnight]

Thanks for that Meaty Weaty. I'll be sure to have a good read of that article!

:-)

[ChrisFlyByNight]

Bring back the good old days when cars and bikes had solid rubber tyres.

[Markyboy]

Run flats are heavier than standard tyres but I am sure you will not notice any major issues in terms of performance and economy. I think they are a great invention and it will not be long before all new cars have them.

[davesdad]

run flats

as an old man I wonder what the fuss is all about on run flats I worked at the late BL when the 1st mini was made and they were offered then they were made by Dunlop if they were fitted the spare was classed as an extra:confused: :confused: :confused: :confused:

[Quilgy]

Speaking of run flats, have you seen Michelin's Tweels? They are are an airless tyre that runs on an inner spoke system. I can't explain it very well - have a look at these two sites, the second is a video of it in action. It would be amazing if these became mainstream.

http://www.autoblog.com/2005/01/04/tweels-are-coming/
http://www.youtube.com/watch?v=fqRJ9GfIJtI

[barryk]

Run Flat Tires Insurance

Didn't see this thread and posted following query under "breakdowns"!

I have a BMW 3 Series Touring with EXPENSIVE tyres. I was told if you do have a puncture they cannot be repaired.Is there an insurance that you can take out to cover cost of new tire if you do have a run flat tyre puncture. I am insured through RAC and they don't seem to cover this!

[Glosphil]

Originally Posted by Markyboy

Run flats are heavier than standard tyres but I am sure you will not notice any major issues in terms of performance and economy. I think they are a great invention and it will not be long before all new cars have them.

Just wait to you have a puncture that damages the tyre and you are 200 miles from the ferry at 9pm and have no spare. Still think run flats are a good idea?

I won't buy a car with runflats and I always remove a space-saver and replace with a full-size wheel & tyre that matches the 4 fitted to the car.

A full-size spare will always allow you to complete your journey - a runflat or space-saver may not due to speed/distance restrictions.

[tazsaab]

Re:Run Flats

All the stuff I've read so far points to some reduction in comfort (ride), opinion seems divided on handling and performance. Personally I run very high performance Saab(s) (modified) and use either Goodyear F1 or Avon ZZ3 tyres. I carry an economy spare for the serious blowout and a can of puncture repair. It's usually enough (using caution) to get me home and a replacement tyre is cheaper than a run flat. I've only driven one car fiited with runflats (a BMW) it was a harsh ride and did not provide the same handling experience I'm used to. Nor did they inspire any confidence. I try out out most of these things at trackdays and on public roads. Runflats get a big thumbs down from me, but it's just my opinion - ask others.
Taz

[galaxymadbaz]

Run Flats

I recently had to change tyres on my galaxy (due to previous owner having wrong load rating, non re-inforced tyres on) I considered having runflats but the guy at Etyres convinced me otherwise saying you are limited to speed and distance on these and they CAN NOT be repaired, tyre pressure has to be very closely monitored and they apparently give a harsher ride. You still have to have them changed so purely on economics I'd go for normal tyres. If you practice you should be able to change a wheel in under 10 minutes, or you could use some squirty stuff in the tyre till it's convenient to have a permanent repair/replacement.
Ford in there wisdom have ommitted the spare wheel on the Mk3 Galaxy, they give you the squirty stuff and offer runflats as an option, I think this is really hurting them as they aint selling (taxis need a spare to get a local authority license) I certainly wouldn't like to travel too far from home with kids without a spare.

[ptr550]

Originally Posted by Jonny Fortnight

Hi guys & gals,

I've just purchased a new car which has run flat tyres. I was wondering if anyone knew much about these. I understand that you can drive on them with a puncture but what I would like to know is, how much will they effect the performance and economy of my car?

Any help and advice would be much appreciated.

A bit of advice for you check TYRE PRESSURE on a regularly as a run flat tyres will look fully inflated with only 5 psi causing it to wear the outside/inside edges resulting in excessive wear and the cost of replacements. I am running BMW 320i with run flats fronts will have to be changed at 9,000 and backs at 10,000 due to me not checking tyre pressures

[bob knight]

not so sure

I have run flats on my BMW 520 no option! standard..:( not impressed may be a ok idea on motaways were roads are very smothe.. very hard ride on lessor roads not what you would expect from a car of this type. The supension rattles and the ride quality suffers. Bring back regular tyres use the squirty stuff if you really cannot manage to get there on time any other way.

[ptr550]

Originally Posted by bob knight

I have run flats on my BMW 520 no option! standard..:( not impressed may be a ok idea on motaways were roads are very smothe.. very hard ride on lessor roads not what you would expect from a car of this type. The supension rattles and the ride quality suffers. Bring back regular tyres use the squirty stuff if you really cannot manage to get there on time any other way.

You can fit standard tyres on your wheels as I checked this out with BMW independant specalist, there is also a kit available form BMW to fit spare wheel. RFT are approx £25 dearer than standard tyres but I will be fitting standard when RFT are scrubbed.:)

[Legionreturns]

The biggest complaint from BMW drivers, on various BMW forums, is that since switching to RFT's the ride has been compromised and you feel the road a lot more. Second in the list of complaints is availability should you require a replacement tyre. A lot of people just simply do not stock these and I know at one point there was a 2 - 3 week waiting period for the 17" plus RFTs

[RoverV6]

Run Flats

This idea is not new. Old Rovers had TD tyres, which meant total deflation, and they could be run flat at low speed for a few miles. The early Metro had 12 1/2" wheels for these also.The new tyres are a different style of make up to enable safer travelling in the event of a puncture.

[bridget]

Run Flats

Originally Posted by bob knight

I have run flats on my BMW 520 no option! standard..:( not impressed may be a ok idea on motaways were roads are very smothe.. very hard ride on lessor roads not what you would expect from a car of this type. The supension rattles and the ride quality suffers. Bring back regular tyres use the squirty stuff if you really cannot manage to get there on time any other way.

Agree!!!!! I hate them, they throw you all over the place and after driving a Golf for over 11 years, I found the change to BMW and run flats incredibly difficult and am still not used to the performance of the Run Flats. My choice, I would not have them. :(

[Rolebama]

My only personal experience with these was whilst working for the AA. Usually in the early hours on the M25, called out to 'puncture no spare' and when I turned up, the member would generally tell me that they had travelled some distance down whatever motorway and that they had heard/felt a rumbling noise. When they pulled over to investigate, they found whichever tyre was shredded. My conclusion was that they had got a puncture some miles back and not realized it. Continued driving had caused the tyre to fail completely. Needless to say, replacement was unavailable at that time, so I could only offer recovery. The general comment from member was that they were unaware of the puncture when it happened.

[myoldcar]

One thing is for sure they are expensive to replace when compared to older tyres.

[Snowball]

On the subject of run-flat tyres, as it is an offence not to have your tyres at the correct specified pressure, could a police officer prosecute you for driving on a punctured RFT, or does the tyre's design parameters overrule this possibility?

[Rolebama]

I spent a long time talking with Traffic Police at Alperton on the subject of run-flats and space-saver tyres. There is no doubt that the use of a space-saver contravenes tyre laws, as does running on a punctured tyre. I was told basically that the Met Police adopted the policy that as they are supplied as OEM, then they may only prosecute if they were proved to be the contributing factor in an accident.

[Snowball]

Originally Posted by Rolebama

I spent a long time talking with Traffic Police at Alperton on the subject of run-flats and space-saver tyres. There is no doubt that the use of a space-saver contravenes tyre laws, as does running on a punctured tyre. I was told basically that the Met Police adopted the policy that as they are supplied as OEM, then they may only prosecute if they were proved to be the contributing factor in an accident.

So yet another situation where we motorists are at the mercy of the jobsworths; no clear cut position because legality has not kept pace with technology. I am now imagining a scenario where a driver is carefully continuing on his way with a space-saver or RFT. Another driver (at fault)then hits him; no witnesses, no clear indication of whose fault it is. If ambulance and police called to scene, the only "obvious offence" is the space-saver/deflated RFT. The chances of prosecution then become dependent on police attitude.

To my mind, the best solution is for the car manufacturers to be pressurised into supplying cars with a conventional spare wheel, with dedicated stowage space. At present, whatever their various excuses for these "alternative wheels", the motorist is left vulnerable, and the only winners are the car manufacturers.

If our government are really interested in road safety, they would make provision of a proper spare wheel mandatory for the legal selling of new cars.

[Rolebama]

That is the problem. Our Governments bow too readily to the whims of the manufacturers, with no apparent regard to the safety aspects which are compromised.
I would add that I have been amazed at the reactions of people who I have kept for the extra few minutes to change punctured rfts to the rear wheels. (And the same with space-savers.)

[Snowball]

It's worse than that, Rolebama. The people in the relevant government offices are not there because they are an informed authority on road and vehicle safety. The jobs are filled with P.C. individuals, who will listen to other P.C. people, and yield to the persuasions of the ones most likely to be beneficial to their careers.

So, not being capable of logical solutions themselves, any sensible legislation that does get through is dependent upon coming from a source valuable to their progress.

Sorry to be so pessimistic, but I am afraid that's how it stacks up.

[MrDanno]

I honestly can't see much advantage of the RFT's. You can only drive something like 50 miles maximum on them and I believe they have to be replaced and not repaired?

While on the subject of legality of tyres, Where would you stand if you have directional tyres and you get a puncture on the wrong side of the car? Your only option is to fit the spare with the wrong rotational direction.

[Sussex Patrol]

Originally Posted by MrDanno

I honestly can't see much advantage of the RFT's. You can only drive something like 50 miles maximum on them and I believe they have to be replaced and not repaired?

While on the subject of legality of tyres, Where would you stand if you have directional tyres and you get a puncture on the wrong side of the car? Your only option is to fit the spare with the wrong rotational direction.

It is ok to do so as long as you treat as a temporary spare-i.e no faster than 50 mph/80km/h and replace as soon as possible.

[ptr550]

I have changed my mind about RFT since i have monitored the pressures the ride and wear has improved are they worth it, well if anyone has a blowout on the motorway i think they may wise they had RFT.:):)