Why do some cars have space saver tyres as opposed to a full-sized spare? Our Motoring Advice team is asked this question all the time. In a nutshell, modern cars are built to be as efficient and aerodynamic as possible, and a big lump in the floor doesn't help with reducing emissions.
Space saver spare tyres or temporary use spare tyres (TUSTs) are common in modern cars. Alternatives include a full-sized spare tyre, run-flat tyres and a tyre repair kit.
If you are carrying a spare, you should check its tyre pressure monthly; all tyres naturally leak air through the walls and the spare is the least checked tyre on the car. A flat spare is as useful as an ashtray on a motorbike!
How to use space saver tyres safely
- Space savers are a temporary spare: their job is to get you to the nearest mechanic or home and out of harm's way.
- They are usually limited to a speed of 80km/h but this can vary, so always follow the manufacturer guidelines.
- You can typically drive a few hundred kilometres on a space saver tyre, depending on the brand and type.
- Ideally, they should be put on the back wheels as opposed to the steered wheels.
- Space saver tyres don’t grip the road as well as normal tyres, which reduces steering and stopping ability.
Pros of space saver tyres
- Space saver spare tyres are more compact than a full-size spare, so provide more usable boot space.
- Space saver spares are lighter, thus reducing fuel use and exhaust emissions because your car’s engine has less weight to pull.
- Space savers cost less than full-size spare wheels and tyres. This saves the car manufacturer money which may be passed on to the car buyer.
- Because space saver tyres come on a conspicuously skinny wheel, often painted bright yellow or orange, they prompt car owners to rectify the flat tyre and return the space saver to the boot. When a full-size spare replaces a flat, the flat often stays in the boot long-term … leaving you stranded the next time you have a flat tyre.
Cons of space saver spare tyres
- Space saver tyres only have a range of a few hundred kilometres before becoming worn out and needing to be replaced. This range is enough to get most drivers home, to a tyre store or a mechanic.
- Space savers are only good for speeds of up to 80km/h, which could slow your progress if you’re out of town and far from the nearest mechanic or tyre store.
- A car with a space saver tyre fitted won’t steer or brake as well as one with four full-size wheels and tyres, particularly in an emergency avoidance manoeuvre.
- The full-size flat sometimes won’t fit in the space saver’s position, so it takes up space in the boot or the cabin.
- With a full-size spare it’s possible to rotate your tyres using the spare, which spreads tyre wear over five rather than four tyres. You can’t do this if you have a space saver spare.
What should you choose?
It really depends on the type of vehicle you are buying and your budget. Space savers are safe and cost-effective if used to manufacturer specifications. If you buy a car with a space saver, be aware of how to use them properly.
Some car boots don’t have room for a full-size spare, which means if you choose to have a full-size wheel and tyre it has to go in the boot – permanently taking up luggage space.
Other cars with a standard space saver have room for a full-size spare, which doesn’t sound like a space saving to us.
Read the pros and cons and be aware that it is sometimes possible to choose a full-size spare instead of a space saver, either at extra cost or as a no-cost option.