What should I do if I get a flat tyre?

Worst flat tyre experience? Three tyres slashed by a bloke who wrongly presumed I was trying to get him sacked…

One flat tyre is a nuisance, three is… well, challenging.

Especially fitted to a car parked in a secure zone three levels below the street. No chance of a tilt-tray truck getting down there, lest it take out sprinkler heads, call out the fire brigade and incur a very costly fee.

So I swapped a slashed tyre at the front of the car for the spare and slowly drove the car up the ramps to street level so that it could be placed on the back of a truck for transport home.

The next morning I drove the car at exceptionally low speeds to the nearest tyre retailer – I won’t do them the disservice of naming them – who sold me three tyres at unfairly inflated prices because they knew I was in no position to shop around, and the tyre sidewalls had been slashed, so they were throw-away jobs. How did I feel after all that?

Deflated…

Flat tyres are troublesome, but thankfully they’re also a rare occurrence these days.

So here’s a few tips for handling different types of flat-tyre scenarios.

While run-flat tyres are not widely praised by motoring journalists, they do serve a useful purpose – saving you the inconvenience and effort of changing a tyre out in the middle of nowhere, at any time of day or night.

The quid pro quo is that you pay more for run-flat tyres, and if one should be punctured, you’ll likely have to buy a new one, whereas a conventional tyre can usually be affordably repaired with a plug or a tube.

Chances are that you’ll learn one of your run-flat tyres has been punctured by an alarm from your car’s tyre pressure monitoring system. If your car is not fitted with such a system, you’ll note the change to the car’s handling and the weight of the steering.

The steering will feel heavier turning away from the side of the car where the punctured tyre is located.

If the punctured run-flat is fitted to the rear, other symptoms you may note include compromised acceleration and more road noise.

What you should do as soon as you detect that one of your run-flat tyres is punctured is reduce your vehicle’s speed to no more than 80km/h and proceed to the nearest point where the tyre can be removed from the car and replaced.

You should not travel any further than an hour’s drive on a punctured run-flat. If you are over 80km from a tyre retailer/repairer, you should call for roadside assistance to help you transport the vehicle safely.

Cars are often equipped with a tyre repair kit to get the car back on the road if the boot is small or the wheel and tyre combinations are larger – sometimes measuring different sizes from front to rear as well.

Most electric cars on sale in Australia also go without a spare tyre, and if they do have one, it's most likely to be a temporary space-saver.

If a tyre should deflate while the car is moving, you’ll either receive an alarm from the tyre pressure monitoring system, or you’ll note worsening weight on one side through the steering wheel, slower acceleration and more road noise.

Pull over at the earliest opportunity, because if the tyre sidewall happens to be damaged, there’s a very strong chance that the tyre repair system will not seal the puncture.

You’ll find the repair kit in the boot, usually under a false floor where the spare tyre would normally reside.

Tyre repair kits in their most basic form comprise a bottle of tyre sealant and an air compressor. While they differ in detail from one manufacturer’s type to another, the principle is the same.

Attach the sealant bottle to the compressor and then attach either a hose from the bottle or the compressor to the tyre valve. The compressor plugs into one of the car’s power outlets (12-volt) and disgorges the tyre sealant into the tyre, plugging the puncture and reinflating the tyre at the same time.

Instructions are usually supplied with the repair kit, and it’s important to follow these to the letter.

There is some doubt as to whether tyre repair kits are effective in all situations, but provided the puncture is not as large as the breach that sank the Titanic, tyre repair kits used properly will get you back on the road again much sooner than a service technician from your friendly motoring association.

Once you’re back on the road, limit speed to 80km/h and visit a tyre retailer for either a new tyre or a repair.

Lift the false floor in the boot of your modern hatchback or SUV and you’ll often find what looks like a motorcycle tyre on a narrow steel rim. This is the temporary space-saver, a tyre that can be identified by the letter ‘T’ on its sidewall, preceding the tyre’s width, profile and compatibility with a wheel diameter in inches.

It will likely also feature the legend: ‘Temporary use only’.

These tyres are to be fitted like a conventional spare tyre, but there are limits to how far/how fast the car should be driven when one of these is fitted.

As with run-flat tyres, the speed should not exceed 80km/h and the car should be driven for no more than an hour. They are there to get you to a destination where the punctured tyre can be fixed or replaced.

For an explanation as to how the spare wheel should be fitted, see below.

Some importers specify large wheel and tyre combinations that won’t fit in the spare wheel well below the boot floor, but the well will accommodate a standard-size wheel as easily as a temporary space-saver spare.

So your car may be fitted with four 19-inch alloy wheels and an 18-inch steel wheel for the spare. Although the spare is likely to be a narrower tyre than the road wheels, the tyre is a conventional type – wider than a temporary spare.

Its rolling diameter will likely be roughly the same as the 19-inch alloy wheel and tyre combination at each corner of the car.

Unfortunately, this type of spare should be treated with the same caution as a temporary spare, a punctured run-flat or a conventional tyre repaired with sealant.

Don’t exceed 80km/h, as the tread pattern is different from the pattern of the other three tyres, and so are the sidewall and contact patch.

The hardness or softness of the compound will vary too. In other words, the car will handle and steer variably in wet or icy conditions. Even in the dry, the car’s dynamics will feel different.

If the spare wheel in your boot is an alloy just like the other four fitted, and the tyre is the same as those on the road wheels, you’re in luck.

This is arguably the safest solution to a punctured tyre.

There is a downside, however. For a start, there’s the weight of the wheel. Alloy wheels larger than 16 inches in diameter can be quite heavy to lift in and out of the boot.

The added weight is often attributable to the wider rubber that goes with these bigger alloys.

But if the tyre is genuinely too heavy to lift out of the boot, there’s always your friendly mobile service technician from a state motoring association or the company supplying your roadside assistance.

Flat tyres (and flat batteries) account for the vast majority of call-outs received by the roadside service providers in this country.

Swapping the punctured tyre for a spare begins with securing the car in place with the parking brake on and leaving the transmission in gear (manual) or in Park (auto).

Use the wheel brace supplied with the car – in the boot – to loosen the wheel fasteners one turn anticlockwise while the wheel is still on the ground. This makes it easier to unscrew the wheel fasteners (nuts or studs) with the wheel off the ground.

Take the jack out of the boot and position it under the jacking point closest to the punctured tyre. Precise information on this subject can be found in the owner’s manual. Check the index at the rear for ‘spare tyre’ or ‘jacking points’.

Raise the car using the jack until the punctured tyre is well clear of the ground. Jacks supplied as original equipment in modern passenger cars are usually of the ‘scissor jack’ type. These are simple devices with a sort of pantograph affair to lift the car by merely turning a long screw with a handle.

Use the wheel brace to remove the wheel fasteners entirely and place them somewhere safe.

Slide the wheel off the hub and relocate it near the boot of the car. Lift the spare wheel into place and line up the holes of the wheel with the studs or the holes in the hub. Fasten the wheel into place with the nuts or studs and tighten in a pattern that criss-crosses the hub.

Lower the car and remove the jack from underneath. Tighten the wheel fasteners as hard as you can with the wheel brace.

Place all the tools back in the boot, and lift the punctured tyre and wheel into the boot as the final act.

You’re now ready to hit the road again, seeking the nearest tyre repair place.

Quick checklist for a punctured tyre
• Run-flat tyre
— Continue driving at a reduced pace; find the nearest tyre retailer
• Tyre repair kit
— Pull off the road in a safe location, repair tyre and drive to nearest tyre retailer at a reduced pace
• Temporary space-saver spare
— Pull off the road in a safe location, change punctured tyre for the spare, resume driving at a reduced pace and find the nearest tyre retailer
• Full-size non-matching spare
— Pull off the road in a safe location, change punctured tyre for the spare, resume driving at a reduced pace and find the nearest tyre retailer
• Full-size matching spare
— Pull off the road in a safe location, change punctured tyre for the spare, resume driving, and don’t forget to have the punctured tyre repaired or replaced as soon as possible