Car tire Ageing: Whether you use the car or you don't, car tires age, primary indications of car tire ageing would be cracking on the side walls, on the treads or fading of the treads, sometimes accompanied by carcass distortion. Old or aged tires must be checked by a tire expert before use to ascertain it's suitability for road usage.

The ramifications of not doing so could prove fatal. One must also pay particular attention to spare tires and tires on caravans and trailers, which often tend to be ignored. It might help to check for tire pressure and conditions before usage.

Mileage: Keep note of the duration of usage of the tires on the car. Normally, tires wear out depending on the number of miles driven, the type of the surface and sometimes even the kind of driving you do. It is generally considered prudent to replace tires after their recommended mileage.

Inflation Pressure: Tires happen to be the only point of contact between the vehicle and the road surface, hence inflation pressure happens to play a vital role in safety driving characteristics, mileage and also fuel consumption. Since there is no "Suggested inflation Pressure" it helps to follow the manufacturer recommended pressure, often found in the log book.
One must not check he pressure when the tires are hot (after a drive perhaps!), its best done before driving away to work once every week when tires are cold. Under inflation can cause tires to wear more on the outside than on the inside, leads to excess heat up of tires, decreases fuel efficiency. Over Inflation causes the tire to wear more on the inside than the outside. However, a little over the recommended tire pressure was found to show better fuel efficiency characteristics.

Misalignment: Tires when not positioned properly, or if not aligned properly, can cause uneven wear either sides of the tire shoulder or both the sides and would have a slightly torn and faded look. Check periodically for wheel alignment, wheel balancing and keep examining the tread patterns every month or so.
Proper maintenance, regular checking for inflation and prudent driving habits can go a long way in ensuring longer life for the tires and safer driving conditions