Beware of your spare

Motorists often breathe a sigh of relief when they have a spare tyre to get them back on the road after a puncture – however – the relief may be short lived as the trustworthy spare in the boot, could lead to other road risks.

Dunlop Tyres SA’s leading technical tyre expert, Keith Phelps said the compact "biscuit" spare can pose serious risks to drivers, passengers, and other road users when used incorrectly, or when not maintained.

“It’s not often that drivers need to haul out the spare tyre from the boot. For many cars, it’s the trusty little biscuit tyre - named for its size. While we may enjoy not using the spare tyre, it does not mean that we must ignore the tyre when times are good. As drivers we must always prepare ourselves for emergencies, and that involves assessing our spare wheel regularly, as well as using it correctly, to avoid additional problems,” said Phelps.

Understanding the biscuit-sized spare tyre

The biscuit tyre - or space saver tyre - is designed to be a temporary emergency solution, that enables a driver to get to the nearest service station or tyre shop to replace/repair the damaged tyre. These compact spares are smaller, narrower, and lighter than a standard tyre, which helps save space in the trunk. However, it’s these very limitations that make them unsafe for extended use.

The dangers of using a “biscuit” spare tyre for too long

1. Reduced traction and stability The smaller tread surface area of a biscuit tyre/space saver tyre leads to less grip on the road surface, especially in wet or slippery conditions. This increases the risk of skidding or losing control of your vehicle – called aquaplaning or hydroplaning - on a wet road surface, particularly at high speeds or during sudden manoeuvres. Be aware of the road conditions and adjust your driving style.
2. Limited speed and distance Most biscuit spare tyres are designed for speeds of no more than 80 km/h and should not be driven for more than 60-80 kilometres. Exceeding these limits can lead to blowouts, handling issues, and even tyre failure. Motorists, especially those driving on freeways and in peak traffic need to exercise caution due to the volume and speed of traffic.
3. Braking and handling risks Because the spare is smaller and thinner than the other tyres, it alters the vehicle’s handling characteristics, affecting steering and braking performance. This becomes even more dangerous when driving on freeways, making emergency stops more difficult.
4. Damage to the car’s suspension and transmission Driving on a spare for too long can cause uneven wear on the tyre and can result in additional stress being placed on the vehicle’s suspension system, leading to costly repairs. In vehicles with all-wheel or four-wheel drive, using a smaller spare can also put excessive strain on the drivetrain, potentially damaging the transmission.

What should motorists do?

• Replace or repair the damaged tyre as soon as possible. The spare should only be used to get to the nearest service station.
• Never exceed the recommended speeds on a spare space saver tyre, or distance limits recommended by the manufacturer.
• Check your spare tyre regularly. A spare tyre left unused for years may be underinflated or may have deteriorated due to the cracking of the tread and sidewall rubber. These signs are a clear indication that the tyres’ compounding properties have diminished and the tyre is no longer safe to drive on.
• Consider investing in a full-sized spare if your vehicle has space for one, providing a safer alternative in case of emergencies.

Stay safe on the road

“While a biscuit spare tyre can be a lifesaver in an emergency, it is not a long-term solution. Driving cautiously and replacing your damaged tyre as soon as possible can prevent accidents, vehicle damage, and unnecessary risks on the road,” said Phelps.

For more information on road safety tips, visit www.dunloptyres.co.za