Had a punctured tyre recently? If so, how did you deal with it? Chances are you didn’t change the wheel at the roadside. Not because you couldn’t be bothered but because spare wheels are considered old tech by most car makers now.
More than 90 per cent of new cars are sold without a spare wheel as standard. Drivers can often specify one as an optional extra (they cost between about £100 and £300 depending on the car), so it’s worth checking whether that box has been ticked by a previous owner if buying a used car.
If it hasn’t, what are your choices and are they any good? We investigate three puncture solutions.
What is a run-flat tyre?
These are called different names by different manufacturers: Self-Supporting Run-flat, ExtendedMobility or Zero Pressure are a few. Whatever the name, the idea is a simple one. A run-flat tyre has a super-stiff sidewall that doesn’t require air to enable the tyre to function as it should. In regular tyres, it’s the pressure of the air contained within the rubber casing that enables a tyre to do its job.
You may not know you’ve had a puncture if your car has run-flat tyres. Tyre Pressure Monitoring Systems (TPMS) actually first came about to warn drivers using run-flat tyres who may not have realised their tyres had lost air pressure.
Your TPMS should warn you about a loss of pressure and although you can continue driving safely, you shouldn’t travel for more than 50 miles. Run-flat tyres can’t be repaired because it’s impossible to tell if the tyre’s integrity has been affected by running without air. And thanks to the more rigid sidewall, drivers can find the ride of their car feels rather hard and unforgiving over bumps.
What about tyre sealants?
Instead of a spare wheel, many new cars come with an aerosol of sealant and a compressor. You attach the sealant to the valve and inject it. Hopefully this should plug the hole when the tyre has air put back into it. You can then use the compressor to re-inflate the tyre. Assuming the tyre doesn’t let go completely and blow out, the sealant should enable you to get home but it’s a temporary repair. You can buy cans of sealant at most car parts retailers. Prices start at £2 but expect to pay between £5 and £10.
Car makers have chosen this option because they are significantly lighter than spare wheels. Tyre experts claim sealants will fix about four in every five punctures, which theoretically makes them about as useful as carrying a spare wheel.
If the tyre is ripped rather than holed, for example by a pothole or kerb, they won’t work. Some drivers say they’ve had trouble injecting the sealant. And although sealant producers claim their product will easily wash out, many tyre outlets remain cynical. This means if you have a simple hole in the tyre that could be legally and safely plugged by a professional, tyre repairers may refuse.
How do puncture-proof tyres work?
For around the last 100 years, as long as cars have had pneumatic tyres, the puncture has been the blight of life as a driver. But now someone has come up with the puncture-proof tyre. The idea is that a rubber gum lines the inside of the tyre. When something like a nail holes the tyre, the membrane ‘heals’ it.
No more stopping at the road side to change a wheel with a tyre that’s been punctured by a nail.
Some experts worry that if nails or screws are left in tyres, they might cause damage that will eventually see the tyre fail suddenly with a blowout. The puncture-proof membrane can’t work on the side walls so isn’t effective against potholes or kerb damage.