Tyres are almost always the mainstays of a vehicle. Whether it is a common car tyre, tractor tyre or truck tyre: unless equipped with a caterpillar track, a vehicle needs tyres in order to be moved on different surfaces. Used and new vehicle tyres for trucks and passenger cars do not dispose of an inner tube, such as a bicycle. The supporting element is the so-called carcass, which consists of either synthetic fibres or steel springs. The carcass of the tyre is protected by the side panel. A bead enables the necessary hold between tyre and rim.
On the basis of specific vehicle characteristics, passenger car tyres and truck tyres can fundamentally differ from one another. External factors such as terrain conditions, vehicle types or weather conditions set the corresponding requirements for the vehicle tyres. Passenger car tyres and truck tyres - whether new or old - are, in the first instance, subdivided into three types: summer tyres, winter tyres, and all-weather tyres. Mostly, tyres are used for several years and replaced through a tyre change depending on the season.
The summer tyre has a minimum tread depth of 1.6mm (according to national standard) and is suitable for warm to moderate weather conditions. It should only be used on streets free of snow and ice. Summer tyres are resistant to high temperatures. Summer tyres are specifically designed for dry streets and can thereby also resist rising temperatures, which result additionally through higher speeds.
Used and new winter tyres for trucks and passenger cars stand out due to their suitability for snowcapped and iced streets. Therefore, they have slat profiles for a better grip. The rubber material, which is generally used for the production of tyres, is softer than that of summer tyres. Thereby the winter tyre remains flexible even at the most varying temperatures. Winter and summer tyres are changed with the onset of specific weather conditions - mostly depending on the seasons.
Besides these two types of tyres, there are also all-season and all-weather tyres. As the name already suggests, new and used all-weather tyres are suitable for different road and weather conditions owing to the quality of their material. Therefore, they can be used both in the summer as well as in winter, and do not need to be changed with the onset of a new season. The disadvantage compared to winter and summer tyres however is that due to the balanced material characteristics and the structure of the all-season tyre, they cannot achieve the same quality of a special purpose tyre for summer or winter. Therefore it is preferable to use winter tyres on strongly snowcapped roads, for example.
There are uniform identifiers to categorise the different types of tyres. S stands for summer tyres, whereas winter tyres are marked with a W and all-season or all-weather tyres with a G. New and used truck tyres are designated with an L. For the latter types, there are separate requirements for their load-bearing capacity due to the characteristics of trucks, much in contrast to new and used passenger car tyres.
On the one hand, the size of the truck tyres must be adapted not only to weather conditions and road characteristics, but also to the high weight of the vehicle and the cargo, as well as the type of axle. Thereby, a distinction is made between truck tyres for steering axles, drive axles and trailer axles, or trailers. Moreover, truck tyres must be particularly solid since the vehicle often covers great distances, whereby the wear of the tyres progresses quicker than with other tyres. The tyre quality of new and used truck tyres distinguishes itself through pressure distribution and rolling resistance. Note also whether the truck tyres are primarily used for construction sites or for drives on highways.
The so-called load index indicates the loads the tyres have generally been designed for. It is recommended to regularly verify the tyre pressure (measured in bar), as this may, amongst others, have an effect on the fuel consumption of the vehicle. Moreover, contact with materials harmful for tyres, such as petrol, oil or diesel, should be avoided at all cost. These can have a lasting negative effect on tyre quality and the longevity of the truck and passenger car tyres, for example in that they cause holey areas or can soften the material.
Such damages, age-related wear and tear as well as the general quality and fitness of the tyres should also be observed at the moment of purchase of used truck or passenger car tyres. Used tyres age steadily. Accordingly, signs of wear can hardly be avoided. Therefore, used tyres should not be older than or have been in use for more than five years at the moment of purchase, since, according to a recommendation by the ADAC, a tyre should not be used for longer than 6 to 8 years. For used truck and passenger car tyres, age and storage should therefore be checked in advance. Also, information on the frequency and purpose of use of the tyres should be made available. The age of the used passenger car or truck tyres can be learned from the DOT-number on the side of the car tyre.
The speed with which new and old passenger car and truck tyres age depends both on the tyre itself as well as on the vehicle, the placement of the tyre on the drive form (rear-wheel or front-wheel drive) and on the way the vehicle is driven. The speed with which a vehicle with a certain tyre may be driven can be learned from the speed index. It ranges alphabetically from the marking A1 (up to 5km/h) till Y (up to 300km/h).
Both new as well as used truck and passenger car tyres that were produced or put on offer within the EU after 1.11.2012 must possess the EU-tyre labelling under the regulation 1222/2009 for tyre labelling. The label is divided into fuel efficiency and wet grip with different classes ranging from A (good) to G (bad). Also, the noise level (the rolling noise of the tyres) is described on the label by means of three soundwave gradations. With this, a uniform framework for mobile security as well as higher efficiency should be achieved. Moreover, the tyre label enables a comparison between different tyres.
Whoever wants to buy new or used tyres has a variety of criteria with which the suitability of the tyres can be checked.