Many people stick to the vehicle manufacturer's recommendation and, in general, that is the best option. However, there are often a number of good reasons for deviating from this recommendation:

1. You may want to upgrade your tyres to a higher speed rating. In this case, you should add 10 per cent to the maximum speed of your car, and then choose a tyre suitable for this speed.

2. Most cars are sold with tyres with good all-round ability. Tyre life is balanced against grip, good wet road ability is balanced against noise, etc, and you may want to change in favour of a bias that suits your preferences.

3. It may be that the tyres approved 10 years ago for your car are no longer in production, so exact replacements are not possible.

4. You may want to change your wheels and therefore find new tyres to suit. No tyre can have all the qualities a good tyre should have, because some of the qualities oppose each other. The hard tyre that lasts a long time cannot grip like a soft tyre; the prominent tread that prevents aquaplaning is noisy on a dry road and has increased rolling resistance. None of these features is utilised to its fullest extent in a tyre selling at a low price, but some of the more expensive tyres are excellent compromises.

1. A tyre for popular family cars. This would be a compromise tyre, with good ratings for tread life, directional stability, steering effort, rolling resistance, noise levels and wet road performance.

2. A tyre for top luxury cars. The qualities would be slanted towards comfort and low noise levels, at the expense of tread life and initial cost.

3. An out-and-out sports tyre, with the emphasis on grip and the ability to stay cool at high speed. A further choice is between cross-ply and radial-ply tyres. The cross-plies are cheaper, flex more, have a higher rolling resistance, and a shorter life, and are gradually disappearing from the marketplace. Radials suffer less tread distortion, grip the road better, last longer, and deliver better fuel consumption.