Carsguide Motoring Journalist Paul Gover changes a tyre on the Skoda Superb during the 2010 Car of the Year testing.
BETTER quality roads and tougher tyres have reduced the rate of flat tyres over the years.
However, thousands of motorists still get stranded by punctures every week and many don't have a clue how to change the tyre. In Queensland alone, the RACQ reports it roadside crews change an average of 5500 flat tyres every month for stranded motorists. But you can avoid being stranded if you follow some simple advice.
The best way to beat a flat tyre is to avoid it in the first place. Punctures are often caused by the sidewall hitting a sharp object because the tyre pressure is too low.
You should regularly check your tyre pressures are at the correct level as stipulated on the plate on the inside of the driver's side door or in the owner's manual.
Service stations supply mechanical and electronic air hoses.
According to an RACQ survey, the electronic ones are more accurate, while the old-fashioned mechanical gauges can be as much as 17.8 per cent out - that's 5.34psi at a 30psi inflation pressure.
To avoid inaccurate readings, buy your own tyre pressure gauge, available from motoring clubs or auto stores.
RACQ technical researcher John Ewing advises that the more you pay, the better the quality. He also rejected the myth that electronic gauges go out of calibration.
"We checked with an instrument maker we know and he said that basically they stay pretty much as accurate as they started out," he says. "The accuracy comes back to the quality of the product you buy at the outset and clearly the better quality gauges are likely to be more expensive."
Motorists should also check their tyres for wear and the presence of foreign objects such as screws and nails. If you discover one, drive to a tyre shop and have the tyre checked. They can be quickly and safely repaired before an expensive and dangerous blowout.
Also, check your spare tyre. There is no point in changing to a spare tyre that is bald or flat. When buying a used car check it comes with a spare wheel and serviceable tyre. A spare tyre is not a roadworthy requirement until you put it on the car.
If you are driving and a tyre has a sudden loss of pressure caused by a puncture, you will notice the steering pull one way. Slow down, indicate and pull off the road as far as you can. Don't park close to a bend, or where there is poor visibility for oncoming traffic. If possible, park on a flat surface with enough room between the flat tyre and the road as possible.
The RACQ also advises motorists to turn on the hazard flashers and consider keeping a high-vis vest in the boot to help improve visibility to other drivers. This is already a regulation in Europe. If you are on a motorway or any location where the vehicle is exposed to being struck by moving traffic, have the vehicle towed to a safe place where the wheel can be changed.
CHANGING THE TYRE
Inevitably you will get a flat tyre on a rainy night in the middle of nowhere. Now is not the time to start learning how to change a tyre. It is best if you have a run-through on the procedure in your own garage with plenty of light and a firm flat - and dry - surface.
A lot of modern cars, particularly luxury and small cars from Europe, don't have spare tyres. This is because manufacturers consider they won't be straying far from the city on to rough roads and that the types of owners of these cars would ring for help, rather than change the tyre themselves.
Some cars have run-flat tyres which will continue to operate up to about 80km/h for a limited distance, allowing you to drive to a tyre service centre.
Others have a canister in the boot which you fit on to the tyre's valve. It releases a "goo" that seals the inside of the tyre and re-inflates it. This is only a temporary measure and you should drive slowly and carefully to the nearest tyre service centre.
Some spare tyres are called temporary or space-saver tyres, which are narrower than the original tyre. Again, drive straight to a tyre service centre at the recommended speed and load ratings. If your car has a temporary or full-size spare tyre, it will be either under the cargo floor covering, under the rear of the car or on the tailgate.
- Make sure the vehicle's handbrake is on securely and the car is in gear.
- Unscrew the spare wheel from its housing and lift it out, careful not to strain your back, lifting with your knees. The wheel brace and jack will be in the boot.
- Find out where the jack goes as you can damage underbody parts, and put your safety at risk, if the wrong jacking location is used. Check the handbook.
- Use the brace to loosen al the nuts on the wheel with the flat tyre. These will be tight and you might have to use your boot to give it a kick.
- Now jack the car up until most of the pressure is off the tyre, but it is still in firm contact with the ground before loosening the nuts further.
- Raise the car a little further so the wheel spins freely. Take the nuts off with your fingers and remove the wheel. Roll it around to the back of the car, out of the way and roll in the spare.
- Lift the wheel on to the bolts and replace the wheel nuts with your hands, careful not to cross-thread them.
- Drop the jack so the wheel is touching the ground and not spinning and then use the brace to wind the nuts in.
- Finally drop the jack all the way down and remove it. Now, screw the nuts on with the brace to the same level of tightness they were before.
- Replace the spare tyre, jack and brace in the boot securely so they don't roll around.
Not yet. Remember to get the original tyre fixed. Don't leave it in the boot and forget about it until another emergency. You should also get your tyre service centre to check the nuts on the tyre you fitted are correctly tightened. You may also want to replace the spare tyre with the repaired tyre so that all operating tyres have the same wear life.