Car Tyre Buying Guide: What to Look For

Tyres are the only parts of a car that touch the road, and they determine stopping distances, wet weather grip, steering response, and fuel economy more than almost any other single component. They are also an area where the marketing language is thick enough to obscure what actually matters, and where the cheapest option and the most expensive option are not always the most and least appropriate choices for your situation.

Reading the sidewall label

Every tyre has its specification embossed on the sidewall. A typical marking looks like: 205/55R16 91V. The numbers and letters mean specific things. The first number, 205, is the tyre width in millimetres across the tread. The second number, 55, is the aspect ratio: the height of the sidewall as a percentage of the width. So a 55 sidewall is 55 percent of 205mm, which is about 113mm tall. A low aspect ratio, like 35 or 40, means a lower-profile tyre with stiffer sidewalls and a firmer ride. The R indicates radial construction. The 16 is the wheel rim diameter in inches. The 91 is the load index, and the V is the speed rating.

The load index tells you the maximum load the tyre can support per wheel, and the speed rating tells you the maximum continuous speed the tyre is rated for. V is 149 miles per hour, W is 168, Y is 186. Fitting a tyre with a lower speed rating than the car is specified for is not just an insurance problem: tyres develop heat at speed and a tyre rated below the car's maximum speed will build excessive heat before reaching its rated limit. Always match or exceed the manufacturer's minimum speed rating.

Premium, mid-range, and budget: where the difference is

Testing by tyre industry publications and independent organisations consistently shows that the gap between premium and budget tyres is most visible in two areas: wet stopping distance and wet cornering grip. A test from a 2024 industry comparison found a stopping distance difference of up to five metres between the best and worst performing tyres when stopping from sixty miles per hour on a wet surface. At motorway speeds, that difference is significant.

In dry conditions, the gap narrows considerably. Many mid-range tyres perform within a few percentage points of premium brands in dry stopping and handling. The cost difference between premium and mid-range is often thirty to fifty percent, and on a car used primarily for urban and suburban driving in good weather, mid-range tyres from established manufacturers represent the better value calculation.

Budget tyres from brands with no independent testing data or no manufacturer reputation are a different proposition. The savings on a budget tyre that performs poorly in wet conditions are not savings in any meaningful sense. Tyres, along with brakes, are one of the areas of a car where the cost floor should not be the primary selection criterion.

When to replace, not just measure

The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tread, around its entire circumference. Wet stopping performance degrades progressively as tread depth reduces below about three millimetres, because the tread channels cannot move water out of the contact patch fast enough. Many safety organisations recommend replacing at three millimetres rather than 1.6mm, and on a car used in wet conditions regularly, this is the more defensible position.

Tyre age matters independently of tread depth. Rubber oxidises and hardens over time, and a tyre with 4mm of tread but seven or eight years old has significantly reduced grip compared to a tyre of the same depth at three years. The manufacture date is moulded on the sidewall as a four-digit number in an oval: the first two digits are the week, the last two are the year. A tyre showing 2316 was made in the twenty-third week of 2016. Most manufacturers consider tyres over six years old to be end-of-life for performance-critical applications, regardless of depth.

Matching tyres and geometry

Fitting new tyres to a car with incorrect alignment will wear the new tyres prematurely and unevenly, and does not produce the full performance benefit of the new rubber. If you can see any sign of uneven wear on the outgoing tyres, have the alignment checked when the new tyres are fitted. Most tyre fitting centres can do a two-wheel alignment check for twenty to thirty pounds. A four-wheel alignment, which checks all four wheels and their relationship to each other, is more thorough and usually fifty to eighty pounds. For a car that drives straight and has no visible geometry issues, two-wheel alignment is usually sufficient at a tyre change.

See the OEM versus aftermarket guide for how brand considerations apply to tyre choices, and the used car inspection guide for what to look for in tyres before buying.

Tyre Pressure and What Under-Inflation Actually Does

The recommended tyre pressure for your car is on a sticker inside the driver's door jamb, not on the tyre sidewall. The sidewall figure is the maximum pressure the tyre can handle structurally, not the operating pressure the car was designed around. Running at the sidewall maximum is too firm for most road use and reduces the contact patch, which worsens wet grip. Running below the door sticker figure has the opposite effect: the tyre flexes more than designed, builds heat faster, and wears both shoulders of the tread prematurely.

Most cars specify different front and rear pressures, and a difference of three to six PSI between axles is common. These are not interchangeable figures. Running higher pressure at the rear than specified on a front-wheel drive car changes the weight distribution at the limit of traction in a way the manufacturer did not intend. Check both axles separately against the door sticker, not a single number from memory.

Pressure should be checked when the tyres are cold, meaning the car has not moved more than a mile or two in the previous hour. A tyre driven at motorway speed for thirty minutes builds pressure of four to six PSI above the cold reading. Checking after a motorway run and adjusting down to the cold specification means you are running under-inflated when the tyre cools. Check in the morning before the first journey, or after the car has been parked for several hours.