Simple car tyre safety checks before going on holiday

The holiday season is fast approaching, and workers all around the country are looking forward to a well-earned break with their families in a pleasant location that is neither work nor home.

But a tyre failure will put a damper on all that quality time with the family. And during the holiday season the chances of an incident or a collision increase dramatically.

So before heading off on a long trip to the mountains or the seaside, take these three simple steps to improve vehicle safety and avoid potential risks.

Naturally, if you're in the slightest doubt that your tyres are safe, replace them before they're subject to a full load of your most precious cargo.

A careful visual inspection will quickly reveal things that you may not have noticed, like a bulge in the sidewall, a gouge or a screw embedded in the tread.

You may get away with running around town on a tyre that's sub-standard, but load the kids and enough luggage in the back for a fortnight away in a destination two hours from home and the prospects of a catastrophic failure increase alarmingly.

If the tyre comes apart while the vehicle is travelling at speed it can be a very dangerous situation, especially if the vehicle is loaded and the weight distribution is less than ideal.

When you inspect each tyre (don't forget the spare, either), do the job properly.

Park the car in the driveway or somewhere else that's safe and away from traffic. Leave the car in 'Park' (or in gear for a manual) with the handbrake on.

Don't be afraid to get your hands dirty by feeling around the tyre for anything that isn't right and shouldn't be present (screws, nails, sharp stones, etc). Pay particular attention to the inboard sidewall, which you may not be able to see.

When you've finished the preliminary check, move the car forward half a metre to check the tread where it had been bearing the load and couldn't be inspected previously.

During your visual inspection, check also for tread depth. If the grooves in each tyre aren't deep enough to channel water away from the tyre, aquaplaning is a real possibility in the wet.

Aquaplaning occurs when the tyre starts skiing across the water, rather than pumping it away on either side. As soon as water forms that blanket between the tyre's contact patch and the road, the car will lose grip because the tyre is not dissipating the water effectively.

As a result, roadholding suffers, as does braking, and even cars fitted with electronic safety systems such as anti-lock braking and stability control will require more time to take evasive action.

When checking the tread depth, look for the tread wear indicators (little bridges across the grooves). If the tyre is worn to the point that the tread wear indicators are making contact with the road, this means the grooves are less than 1.6mm in depth and the tyre needs to be replaced; it's no longer roadworthy and will be unsafe on a waterlogged road.

Remember too that tyres often wear unevenly. If a car is set up with a lot of negative camber in the suspension, the tyres may wear faster inboard. Too much toe adjustment one way or the other can also wear the tyres unevenly. So too can over-inflation or (as is more usually the case), under-inflation.

In other words, check for tyre wear across the entire width of the tread, not just the outboard edge of the tyre. If the tyre tread pattern is 'chopped out' on one side or in the middle (due to over-inflation), you need to replace the tyre altogether, even though the tread may be deep enough elsewhere.

You should be able to see the inboard section of the tyre's tread pattern anyway, but crank the steering wheel over to full lock to check the front wheels and poke your head under the rear of the car to check the tyres there.

If the car is too low, you could jack it up, or park it on a driveway ramp to leave enough room at the rear to look underneath. You may need to use a torch if it's too dark.

Tyre manufacturers will often help you find tread wear indicators with the letters 'TWI' or an arrow on the sidewall close to where the bridge is located. If the groove is wide enough, you can actually poke a finger in it and feel around for the indicator.

The blue line across the tread pattern of the tyre in the picture below highlights the wear indicators and the arrow.

If your vehicle is heavily loaded for a holiday stay out of town, you might want to consider boosting the tyre pressures in the rear, but stay within the specifications listed on the tyre placard (usually on the frame of the car inside the driver's door) so you don't over-inflate them.

Of course, once you're back from your holiday you should reset the tyre pressures to what the vehicle manufacturer recommends for a lightly loaded car.

During the course of the year, owners often neglect tyre pressures (which is not something we recommend, needless to say), but tyre pressures are critical on the road with the extra weight of the whole family and luggage on board.

Leave tyre pressure too low and the sidewalls will sag under the weight, generating more heat, using more fuel, and eroding the car's dynamic safety.

Check the tyres and readjust the pressures when the tyres are cold (ie: at a service station just around the corner).

Experts recommend checking tyre pressures every fortnight, which for many vehicle owners would be every second visit to the service station to refuel.

As a final point, if your car has an inflatable space-saver spare, like the one pictured, don't try to inflate it while it's in the boot.