On this page
- How does a tyre repair kit work?
- How does a space-saver spare wheel work?
- Kit or space-saver: comparison table
- When isn't a repair kit enough?
- What should you do after using a kit or space-saver?
- Can a space-saver be fitted in any wheel position?
- No kit or space-saver, or you'd rather not use them?
- Frequently asked questions
How does a tyre repair kit work?
A repair kit works by injecting a liquid sealant into the tyre which, as the wheel turns, seals the hole from the inside. The compressor included is then used to bring the tyre back up to the specified pressure.
- Make the vehicle and everyone in it safe.
- Read the instructions printed on the kit: procedures vary from model to model.
- Connect the sealant and compressor to the valve and inflate to the specified pressure.
- Drive a short distance at moderate speed to spread the liquid, then recheck the pressure as instructed by the kit.
If the pressure doesn't hold, the damage is probably too large for the kit.
How does a space-saver spare wheel work?
A space-saver is a reduced-size spare wheel that you fit in place of the punctured one. It's narrower and lighter than a normal wheel, so it takes up less room in the boot.
For that very reason it's designed for temporary use: the maximum speed is marked on the space-saver itself (typically 80 km/h) and road holding is lower than with a normal wheel. It's meant to get you to a tyre specialist, not for carrying on driving as normal. If you have trouble changing the wheel you can ask for a wheel change.
Kit or space-saver: comparison table
| Repair kit | Space-saver | |
|---|---|---|
| Damage it can handle | Small holes in the tread only | Any damage: the punctured wheel is removed |
| Cuts and shoulder damage | Doesn't work | Can be dealt with (you change the wheel) |
| Do you need to jack the car up? | No | Yes, with jack and wheel brace |
| Speed afterwards | As instructed on the kit | Maximum marked on the space-saver, typically 80 km/h |
| Duration | Temporary | Temporary |
| Effect on a later repair | Sealant can make it more complicated | None on the punctured tyre, if it wasn't driven while flat |
| Afterwards | Tyre must be checked | Tyre must be repaired or replaced |
When isn't a repair kit enough?
The kit isn't enough when the damage is a cut, a tear, a hole on the shoulder or sidewall, or when the tyre has been driven a long way while flat or has come off the rim. In these cases the sealant can't seal the damage.
Nor is it enough on a tyre with a bulge: the problem is structural, not a hole. If your car has neither a kit nor a space-saver, read the page on having no spare wheel.
What should you do after using a kit or space-saver?
After using a kit or space-saver you must have the damaged tyre checked as soon as possible. Both solutions are temporary.
- With the kit: tell the technician you've used sealant, so they can remove it and inspect the tyre.
- With the space-saver: stick to the maximum speed, avoid long distances and refit a normal wheel as soon as possible.
- If the vehicle has a tyre pressure monitoring system, check the handbook: after a repair or wheel change a reset may be needed (see tyre pressure warning light).
Can a space-saver be fitted in any wheel position?
A space-saver can generally be fitted in any position, but some manufacturers recommend specific precautions, for example on four-wheel-drive vehicles or when the punctured wheel is on a driven axle. The correct instructions are in the owner's handbook.
Also check that the space-saver's pressure is correct: it's shown on the space-saver or in the handbook, and it's common to find it deflated because it sits unused for years.
No kit or space-saver, or you'd rather not use them?
If you're in Milan or the surrounding province and don't want to use a kit or space-saver, SOS Tyre comes out to you 24/7, in 30 minutes on average: we assess the damage, fit your spare wheel or, where possible, repair the tyre. Call +39 377 326 0999 or send an assistance request.
Frequently asked questions
Does a repair kit work with a nail still stuck in the tyre?
The instructions for many kits say to leave the foreign object in the tyre, but the procedure varies from product to product: always follow what's printed on the kit. In any case the kit is only designed for small holes in the tread, not for cuts or damage to the side.
Does the sealant in the kit have an expiry date?
Yes, sealant canisters normally carry an expiry date. An expired product may not work properly. Check the date on the bottle during routine maintenance and replace it if necessary, following the vehicle manufacturer's instructions.
Can I drive on the motorway on a space-saver?
You can, but only within the maximum speed marked on the space-saver, typically 80 km/h, and only for the distance needed to reach a tyre specialist. On fast roads such a low speed compared with other traffic calls for great care: consider leaving at the first opportunity.
Where is the space-saver in the car?
It's usually under the boot floor, together with the jack and wheel brace. On some vehicles, such as SUVs or vans, the spare wheel may be mounted under the body or on the tailgate. Many recent cars have no space-saver but a repair kit instead.
Does the kit work on a completely flat tyre?
It can work if the cause is a small hole in the tread and the tyre has stayed properly seated on the rim. But if you've driven a long way on the flat tyre, the structure may be damaged and the tyre, even if it holds air, must still be replaced.