Tyres 225/45 R18

On the sidewall of the tyre you have now, written as 205/55 R16 94T: the width in millimetres, the sidewall height as a percentage of it, the rim diameter in inches, then the load index and the speed rating. The same line is in the car's registration document and usually on the sticker inside the driver's door.

Fuel efficiency and wet grip are graded A to E, A being the best; the noise figure is the measured pass-by noise in decibels. The block above shows this tyre's own classes, and the EPREL link opens its entry in the EU register.

Studded tyres grip best on bare ice; friction tyres are quieter, wear the road less and suit city driving and milder winters. Both are winter tyres. Studs are allowed only during the winter season, so check the dates where you drive.

XL marks a reinforced casing that carries more at a higher pressure, and it is part of the designation: 205/55 R16 94T and 205/55 R16 94T XL are different tyres. The specification above states what this tyre's load index carries in kilogrammes and what its speed rating permits in km/h; compare both with the figures in the car's registration document. Higher is always allowed, lower is not, except that a winter tyre may carry a lower speed rating where national rules allow it.

Yes — the quantity box takes any number. The price above is per tyre and the line under it is the set of four, which is the quantity the page starts at, because four of the same tyre is what keeps the car's handling even. A pair should at least go on the same axle.