There was a time when a new car came with five identical wheels and tyres – four on the road and a spare in the boot.
But with alloy wheels now commonplace but more expensive than the steel wheels they’ve replaced, and car manufacturers looking for opportunities to cut costs, space and weight, you’re lucky to find a spare wheel in the boot at all.
There may just be a tyre sealant and inflator kit but if there is a spare then the chances are it’ll be a non-standard spare designed for temporary use only, and considerably narrower than your standard road wheels and tyres.
Tyres on the same axle must be of the same size and aspect ratio
- Aspect ratio is the height of your tyre’s sidewall as a percentage of its width
- Your car will fail the MOT if mismatched tyres are fitted
- The law makes an exception for temporary use spare wheels fitted in an emergency
Space-saver wheels are designed for temporary use, to get you to a place of repair.
There’s no maximum distance but the speed restriction, limited tread (only 3mm from new) and softer rubber compound mean that the distance covered before repair shouldn’t be excessive.
- Check your handbook and any labels on the spare itself
- Maximum speed is usually restricted to 50mph for safety reasons.
- Use of the temporary spare may be restricted to ‘front only’ or ‘back only’ for safety reasons
- to avoid interference with braking components, or
- to avoid transmission damage
- Handling will be different with a skinny spare fitted and you’ll need to allow for this when driving.
- Aim to get the original car tyre repaired or replaced as soon as possible.
Caravans and trailers
If you’re towing a caravan or trailer and get a puncture, then it's usually OK to fit a space-saver spare to any axle on the car.
Check the handbook though as there might be vehicle-specific advice.
With the skinny-spare fitted and a van on the back you must drive straight to a tyre specialist for a repair or replacement rather than attempt a long journey.
3 February 2017