Tyre sealant, spare wheel or Multiband: what each one does

Sealant repairs small punctures in the tread for long enough to reach a workshop, and a spare wheel replaces a flat tyre once you have stopped. A Multiband does neither: it keeps a burst tyre on the rim while you pull over, so these three things do different jobs and work best together.

Each one helps at a different moment. A slow puncture and a highway burst are very different events.

Tyre sealant kits

A sealant kit is a bottle of sealant and a small compressor. You inject the sealant into the tyre and pump it back up. The sealant plugs the hole from the inside.

What it does well: It is light, takes up little space and can get you moving again after a simple nail puncture in the tread.

What it does not do: The limits are strict. As an example, Kia's owner's manual sets out these limits for its kit:

• It may not work on damage larger than about 4 mm.
• It must not be used on sidewall punctures. Only the tread area can be sealed.
• It is for one tyre only, not two or more flat tyres.
• It must not be used on a tyre badly damaged by running flat or at very low pressure.
• You should stay at or below about 80 km/h, for up to 200 km, on the way to a workshop.
• The sealant has an expiry date.
• If the tyre will not reach the proper pressure, you should stop driving and call for help.

Limits differ between kits, so read the instructions for yours. A sealed tyre is a temporary measure. Have it repaired or replaced as soon as you can.

Sealant cannot help with a burst. A tyre that has split or torn is beyond what a kit can seal.

Spare wheels

A spare wheel replaces the damaged wheel, so you can drive on once it is fitted. There are two kinds.

Full-size spare. This matches your other wheels, or close to it. Once fitted and at the correct pressure, it lets you continue normally, subject to your owner's manual.

Temporary or space-saver spare. This is smaller and lighter, and it is designed only to get you to a workshop. Ireland's Road Safety Authority says a temporary-use spare must not be driven above 80 km/h and may only be used to reach the nearest place of repair. Rules and limits differ by country and tyre, so check the marking on the tyre and your owner's manual.

What it does well: A spare deals with almost any tyre damage, including sidewall damage and bursts, because the whole wheel is replaced.

What it does not do: It does nothing while the car is moving. It can only be used after you have stopped, somewhere safe. Changing a wheel beside live traffic is dangerous, so on a highway you should move away from the road and call for recovery. See what to do when a tyre bursts.

A spare also needs looking after. Michelin advises checking a spare's pressure at least once a year and inspecting it for cracks or damage. It applies the same ten-year limit to spares as to other tyres, even if they have barely been used. A spare that is flat or perished when you need it is no use to you.

The Tyron Multiband

The Multiband is a band fitted in the wheel well, under a normal tyre. After a sudden loss of air, it keeps the flat tyre seated on the rim, so you keep your steering and brakes and can pull over under control.

What it does well: It works at the moment the tyre fails, with nothing for you to do. It is fitted once and refitted at each tyre change by any tyre fitter, ideally a Tyron certified workshop. It is tested to 250 km/h, and in TÜV testing it completed 3 km at 80 km/h then 3 km at 50 km/h through a handling course and slalom.

What it does not do:

• It does not prevent punctures or bursts.
• It is not a run-flat tyre. You can drive on the flat tyre for a medium distance at reduced speed to reach a safe place, but not for long distances.
• It does not repair anything. A tyre that has been driven flat should be treated as damaged and replaced or inspected by a tyre professional.
• It does not replace your spare wheel or repair kit.

You can read more about how it works.

Which one helps when?

Slow puncture from a nail in the tread. Sealant or a spare can both help. The Multiband plays no real part if you notice in time.

Sidewall cut. Sealant will not work. Fit a spare or call for recovery.

Burst at highway speed. Of these three, only the Multiband works while the car is moving. Once you have stopped safely, use your spare or call for recovery.

Two flat tyres. Sealant kits and a single spare both fall short. Call for recovery.

How to choose

These options work together, so you do not have to choose just one. Keep a working spare or kit in the car, know its limits, and save a recovery number in your phone. If you are also concerned about keeping control in a burst, bands are fitted to all four wheels. You can get a quote for your car here.