Car Care: Pros and cons of run-flat tyres
Argument centres around cost and potential inconvenience, writes Jack Biddle
BMW New Zealand says run-flat tyres are the best thing since sliced bread. It’s no surprise then, to find they are fitted to all its new vehicles apart from the M series and M performance cars.
But a BMW owner who contacted Driven has a slightly different opinion.
In the past nine months he has paid around $1500 in replacement tyre costs for his 2008 320i after two punctures and a Warrant of Fitness rejection.
A run-flat tyre (RFT) is basically a self-supporting tyre which, because of its stiff sidewall construction, is designed to allow a vehicle to be driven at a reduced speed and for a limited distance, if the in-cabin air pressure monitoring system indicates an under-inflated or flat tyre. It also eliminates the requirement for design teams to compromise and make room for a spare wheel and associated tools.
On the surface, it sounds like the perfect answer. But not everyone in the industry agrees.
A couple of out-of-town tyre-shop owner/operators I spoke to said RFTs were not repairable if punctured, and expensive to replace.
They didn’t stock them, or have the correct equipment to remove the old or to fit a new RFT if asked. And changing to non-RFTs isn’t straightforward, and potentially adds more costs.
We shouldn’t forget in this debate that not every non-flat-run tyre is repairable either; the warrant reject that our reader suffered may have been because the tyre failed to meet the correct standards.
The argument against RFTs seems to be centred around cost and potential inconvenience especially if owners venture outside the main city limits and are unlucky enough to suffer a puncture or tyre damage.
So what are the advantages? And do they outweigh the negatives? We asked BMW New Zealand some key questions:
Why does BMW use RFTs?
● The tyres offer enhanced convenience and safety because, in the event of a puncture, the driver no longer has to change a tyre on the side of the road.
● They don’t suffer from sidewall blowouts and can therefore help prevent accidents.
● Their inclusion also contributes to enhanced boot/ luggage space, as there is no need to carry a spare tyre.
● They also reduce the vehicle’s running weight, which in turn enhances fuel efficiency.
How far can you drive with a puncture and at what speed?
● BMW recommends a safe distance of up to 80km at speeds of up to 80km/h.
Are the tyres repairable?
● Best practice is that RFT are not repairable.
Why are they so expensive?
● They are more expensive because there are additional manufacturing costs. For example, the sidewall of the tyre is made of thicker rubber and has been reinforced to make it stiffer. ● There is also a BMW Group Tyre and Rim Insurance product available. The base policy covers three years and costs $750 (conditions apply).
As we expected, BMW’s answers are all positive.
So do you have an opinion?
Have you had a good or a bad experience with a run-flat tyre that you would like to share?
Are they better/worse than a space-saver spare or an aerosol canister of sealant provided to attempt a flat tyre repair?
I’m all about reducing running costs and inconvenience, so I will stick with conventional tyres.
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