A smart driver knows it’s wise to keep a spare tyre in your vehicle for those unexpected times when you get a flat or a puncture, and can’t call on a mobile tyre service to come straight away. A spare tyre will get you through that initial hurdle of a damaged or flat tyre, and you can sort out your tyre repair later.
But how much later?
In this article we’ll take a look at spare tyres and understand how long you can safely drive on them. We’ll look at the two types of spare tyres you could have on your vehicle—full-size spare tyres or space saver tyres.
Full size spare tyres
Full-size spare tyres are usually seen in older vehicles that have the space to store them. Cars manufactured prior to the 1990s usually came with a set of five matching tyres—four on the wheels and one in a storage space in the vehicle.
If you get a puncture or flat and you have a full-size spare tyre, you can simply replace the damaged tyre with your spare, and you’re good to go. As long as the full-size spare is in good condition, is not too old, and is properly inflated, there’s no limit to how long you can drive on the full-size spare.
The downsides to carrying a full-size spare tyre
Because these tyres are large, the cars that hold them are also slightly larger. Extra storage cavities on your vehicle add weight. Then with the weight of the tyre added, overall you end up carrying a larger load, and use more fuel.
Full-size spare tyres are also bulky, so if you have a more modern car without a space designed to house the tyre, then you might need to store the tyre in the boot, which leaves less space for luggage.
For these reasons, most modern cars tend to come from the manufacturer with a space saver tyre, which we’ll talk about later.
Factors to consider when using a full-size spare tyre
A well-kept full-size spare tyre should be fine to drive on for unlimited periods of time. However there may be reasons why a full-size spare tyre shouldn’t be driven on for long.
Your spare is too old
Even if you don’t use a tyre, the materials within it will still degrade over time. An in-use tyre should be replaced generally every 2-3 years, and every 5 years at a maximum. Since your full-size spare has been in your car unused, it may not need replacing as often, however if it is 10 years old or more, it should be discarded and replaced.
In the meantime, when you do your periodic tyre checks on your spare tyre, check it for any cracking or dry rot. If these are present, avoid using the tyre.
The tread on your spare tyre doesn’t match the other tyres
If you’re using a full-size tyre as a spare, it should ideally match your other tyres in size and tread. If you aren’t sure how to match the tread, a tyre specialist can help.
Your spare tyre is the wrong size for your vehicle
It’s important to use the right size tyre for your vehicle. Using the wrong size spare tyre can pose hazards. If you have to do it, you should drive at a reduced speed and only between the location where you changed the tyre and the tyre repair shop. Ideally, you’ll ensure your spare is a match.
If you aren’t sure how to match your tyres, a tyre specialist can help you find the best tyre for your vehicle.
Your spare tyre is incorrectly inflated
Like your other tyres, your spare needs to be correctly inflated. If it is under or over-inflated, it won’t perform its job correctly, and may lead to instability when driving, or an increased likelihood of puncture.
Your spare tyre can lose pressure even when not in use, so it’s recommended you check your spare tyre pressure at least monthly. The easiest way to achieve this is to make this part of your regular tyre pressure check.
Space saver tyres
Space saver tyres (also known as ‘donuts’ or ‘temporary use spare tyres’) come in many modern vehicles, and are narrower than the other tyres on your car. They’re also lighter than full-size spares, and take up less space in your vehicle, meaning you carry less weight. With less weight to pull, fuel efficiency is increased and emissions reduced.
Space saver tyres are only meant to be used temporarily. Basically, you drive on them from the location where you attach the space saver to the garage or mobile tyre shop for the repair. You shouldn’t use them to drive around on until you get around to replacing or repairing your damaged tyre.
Aside from taking up less space in your vehicle, there are other advantages to space saver tyres. Firstly, they’re cheaper to replace than full-size spare wheels and tyres. Also, their thin wheel is usually painted in a bright colour to ensure you remember it’s a different tyre to the rest. This is a good reminder that you need to replace it.
On the downside, when you use a space saver tyre, you need to then find space in your vehicle for your damaged full-size tyre. If you happen to have your car loaded up with passengers and luggage, this may be a challenge.
How far can you drive on a space saver tyre?
It’s recommended that you drive less than 80 km on a space saver tyre, however this distance may vary depending on the tyre. Check the manufacturer’s instructions.
Other guidelines when using a space saver tyre
- Don’t exceed 80 kph when driving on a space saver tyre. If the tyre has a sticker advising a lower maximum speed, follow the recommended speed. Also remember to further reduce your speed in the rain.
- Drive directly to a tyre repair service or call a mobile tyre shop so that they can come to you. Don’t exceed the recommended distance your space saver tyre can travel (usually 80 km).
- A space saver tyre will not perform as well as a full-size tyre. Due to its thinness, there’s less rubber gripping to the road, so your vehicle’s handling and safety will be impacted. Lowering your speed when using a space saver tyre is advised, particularly if you are rounding corners, as a space saver tyre may reduce your grip on corners by up to 15% and lengthen your braking distance.
Advice about using a space saver tyre and wheel
Before attaching a space saver tyre and wheel, heed the following advice.
- You should never attach more than one space saver tyre to your vehicle at a time, as vehicle handling could be dangerously hindered.
- Only use a space saver tyre designed for your particular vehicle. If you have replaced the space saver tyre with one that is not part of its original equipment, it could pose a safety risk when driving.
- For front-wheel drive cars, it’s best to keep two regular and functioning tyres at the front, as the front tyres are used for important jobs like braking and steering. So, if your flat is at the front, move one of your functioning rear tyres to the front, then place the space saver tyre at the rear.
- For standard rear-wheel drive cars, install the space saver at the rear.
- For rear-wheel drive cars with a limited-slip differential, place the space saver at the front, otherwise you may damage the differential. (If your flat is at the rear, you’ll need to move a front tyre to the rear, and place the space saver at the front. Then drive much slower than 80kph until you reach your tyre repair shop.)
Can you use a space saver tyre if you’ve already used it?
It depends. A space saver tyre should not be used for distances above 80 kms, when driven at recommended speeds (80kph or less). Therefore, if you only drive 20 kms from when you attach the space saver to where you get the tyre fixed, then you still have 60 kms of use remaining with that space saver tyre.
Of course, you still need to check it for wear and tear after your drive, and it’s a good idea to get the tyre specialist to give it a once over, before you return it to your vehicle. You might also leave some sort of marking on the tyre noting the kms travelled, as you may not remember next time.
If you have used it for 80 kms, or if it has degraded, you need to get a replacement space saver tyre. As mentioned earlier, ensure the space saver tyre you choose meets your vehicle’s manufacturer’s specifications.
Alternatives to spare tyres
Inflation kits
These days, some vehicles include just a tyre inflation kit, or ‘breakdown kit’. This is basically a DIY repair kit that temporarily solves minor flat tyre problems (it won’t help with a blowout).
The kits include an air compressor and sealant liquid. You insert the sealant into the flat tyre valve, then inflate the tyre using the compressor.
A repair like this will allow you to drive for approximately 80 kms at 80 kph max. It relieves you of the effort of changing a tyre, and of carrying around a space tyre in your vehicle. However it does mean that the tyre you ‘repaired’ cannot be used again, whereas if you change a tyre with a small puncture, there’s a chance a tyre repair specialist can fix it.
Run-flat tyres
If your vehicle happens to be fitted with run-flat tyres, then you won’t need to carry a spare. Run-flat tyres are designed to continue to be driven on after a puncture, albeit at reduced speeds and for shorter distances.
The downsides of run-flat tyres is they are more expensive than standard tyres, they can make for a bumpier ride, and they don’t necessarily handle damage to the sidewall of a tyre. For these reasons, run-flat tyres are less likely to be the chosen option for the majority of drivers.
In summary…
With advances in tyre design, better quality materials, and more options for tyre repair after puncture, tyre blowouts and flat tyres are less likely than they once were. In the event that they happen, you are still likely to use a spare tyre of some variety, at least until you reach a tyre repair specialist.
When you do need that tyre repaired or replaced, contact Jim’s Mobile Tyres. We can come to you and repair or change your tyre onsite. For more information on our service areas, and on our range of tyre services, contact us today.
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