At one time if you got a flat tyre, fitting the spare was the only real option to get you back on the road.
But now, depending on how your car is equipped, there’s a multitude of possibilities – some more practical than others.
Space saver wheels
These spare wheels are a common feature of many new cars and even some 4WDs.
- Often brightly coloured
- Very different in appearance and size to what’s normally fitted to the car
- Lighter and take up less space in the vehicle.
Temporary use spare wheels
- Full sized steel or alloy wheels that differ in size and appearance to the wheels normally fitted to the vehicle.
Both space saver and temporary use wheels have a couple of things in common:
- they are only intended as an emergency replacement to get the vehicle to a place of repair, and
- the maximum allowable speed when one is fitted is limited to 80 km/h.
This lower speed limit is imposed because the vehicle’s handling and dynamics will be compromised with a mismatched wheel fitted.
In addition, space saver tyres also have reduced tread depth that effectively limits the distance they can travel.
Another often overlooked issue, particularly for sports cars, is that there may be insufficient space to store a full sized wheel when the spare is in use.
But while space saver and temporary use spare wheels may have practical limitations, they are still a better option than so called inflator or mobility kits. These single use kits are becoming more popular with vehicle manufacturers looking to completely dispense with spare wheels. Such kits generally incorporate either a battery powered air compressor and a tyre sealant, or pressurised containers of sealant that also inflate the tyre.
These products have significant practical limitations as they are generally only capable of temporarily sealing small punctures. In cases where the puncture is large or the wheel or tyre is damaged, they offer no assistance and the vehicle will have to be towed. Ultimately though, it may not be possible to determine if the kit will reinflate the tyre without trying it.
Other notable disadvantages are:
- They usually only provide a temporary solution to allow the car to be driven to a repairer.
- The kit can only be used once. Replacement is then required.
- Replacement kits can be in the order of several hundred dollars.
- In some cases, the tyre must be replaced after sealant is used, regardless of whether it would ordinarily have been repairable.
- The sealants used often have a shelf life and must be replaced after a certain period, even if they haven’t been used.
Based on our experience the bill for a flat tyre for a vehicle fitted with high performance tyres and an inflator kit could easily run to around $1,000.
Run flat tyres
A small number of vehicle makers choose to fit run flat tyres as standard equipment.
- These vehicles do not generally have a spare wheel, or in some cases even a place to store one.
- As the name implies, these tyres are capable of continued use when deflated.
- For some people this will be a positive as they don’t have to deal with a flat tyre at the roadside.
- Maximum usage speeds and distances for a deflated run flat vary, but 80 km at 80 km/h is a common recommendation.
- Cars fitted with run flat tyres must also be equipped with a tyre pressure monitoring system as the driver is unlikely to be able to detect a deflated tyre.
- Run flat tyre side walls are stiffer so ride quality can suffer
- Some run flat tyres are not repairable once punctured
- Replacements are not as readily available compared to conventional tyres
- The range of replacement tyres is not as great as not all tyre manufacturers make run flats
- Run flat tyres are more expensive
- Special equipment is needed to remove and refit them
Do your research before buying
RACQ opposes the use of anything but a full sized spare wheel, as some of the current alternatives can produce practical issues and impose significant operational restrictions on the vehicle when in use. This is a particular issue in outback or country areas where the vehicle may have to be driven several hundred kilometres, at reduced speed, before a suitable repair facility can be found.
We recommend that vehicle buyers always check the type of spare wheel supplied and what provision is provided for spare wheel storage. This may allow the opportunity to negotiate the supply of a more appropriate alternative as part of the purchase.