Tyres and the roadworthiness test: what is checked?

What is checked on the tyres at the roadworthiness test?

At the test, the inspector checks that the tyres are in a fit condition for the road and suitable for the vehicle. In particular they look at:

• tread depth;
• sizes and specifications compared with the approved ones;
• visible damage: cuts, bulges, cracks, exposed cords;
• abnormal or uneven wear;
• consistency between the tyres on the same axle.

What is the minimum tread depth?

The legal minimum tread depth for cars is 1.6 mm (Article 79 of the Italian Highway Code and EU rules). Below this value the tyre is not considered roadworthy.

For safety, many people advise replacing tyres before reaching the limit, because a shallow tread increases the risk of aquaplaning in the wet. Many tyres have small tread wear indicators in the grooves to help you see how much is left.

Do the tyre sizes have to match the registration document?

Yes, the tyres fitted must be among the sizes approved for your vehicle, listed in the registration document. If you fit a size other than those specified, the vehicle may fail the test.

The size is printed on the tyre sidewall: the guide on how to read your tyre size explains what each figure means, including the load index and speed rating.

Will a bulge or a cut make you fail the test?

Damage that compromises the tyre's safety, such as a bulge on the sidewall or a deep cut, can lead to a fail. Regardless of the test, a tyre with a bulge must be replaced.

Find out why in the guide on a bulge in the tyre. For cuts, the criteria explained in when a tyre can be repaired apply.

How do you check your tyres before the test?

Before the test you can do a quick check in a few steps:

1. look at the tread: if the wear indicators are flush with it, the tyre needs changing;
2. check the sidewalls, inner and outer, for bulges, cuts and cracks;
3. make sure the two tyres on the same axle are the same size;
4. check that the size is among those in the registration document;
5. set the pressure to the values given by the manufacturer.

If you notice different wear between the inner and outer edges of the tread, there may be an alignment problem: see steering wheel vibrations and a car that pulls to one side.

Is the spare wheel checked?

The check mainly covers the tyres fitted to the vehicle. It is still good practice to check the spare wheel or space-saver too, because in the event of a puncture it needs to be inflated and in good condition.

A flat or damaged space-saver is no help when you need it: check its pressure from time to time.

Flat tyre just before the test in Milan?

If you find yourself with a flat tyre a few days before the test, SOS Tyre comes out 24/7 across Milan and its province, in 30 minutes on average, to wherever the vehicle is. Call +39 377 326 0999 or use the request for assistance; if you need a new tyre, we check the size and availability with you on the phone.