New tyres
New tyres fitted where the car is parked
Having new tyres fitted at the car saves a trip to a tyre centre and a wait in a reception area. The work is the same as in a workshop: the old tyre comes off the rim, the new one goes on, the wheel is balanced and refitted, and the nuts are tightened to the maker's torque figure.
Reading the size on your sidewall
The size is the string of figures on the tyre wall, such as 205/55 R16 91V. The first number is the width in millimetres, the second is the sidewall height as a percentage of that width, R means radial construction and the last number is the rim diameter in inches.
The part after the size, 91V in that example, is the load index and speed rating. A replacement should match or exceed both, and the two tyres on one axle should be the same size and pattern.
Budget, mid-range or premium
Tyres fall roughly into three tiers. Premium brands usually stop shorter in the wet and often last longer; budget tyres cost less up front but vary more in quality.
The label on most new car tyres grades wet grip, fuel efficiency and outside noise, which is a fairer guide than the brand name alone. For a car doing high mileage or plenty of motorway driving, look at the wet grip grade first.
Signs a tyre is due for replacing
Tread close to the legal minimum is the obvious sign, but it is not the only one. Fine cracks that open up when you squeeze the sidewall, a bulge, exposed cords or uneven wear on one edge all mean the tyre should be looked at.
Tyre safety groups suggest thinking about new tyres at 3 mm of tread, because stopping distances in the wet grow noticeably below that depth.
What the fitter needs at the car
A driveway, a residential street where parking is legal or a workplace car park all work. The jack needs firm, level ground and there has to be room to work around the wheel.
Supermarket, retail park and station car parks are private ground, so the owner's permission comes first.