Welcome to Phillips Tyres in Oxford. On our website, you will find a vast variety of 4x4 tyres in most sizes and at the very best prices. Please have a look.
On this page, we would like to give you some advice and information about 4x4 tyres.
The selection of the optimal 4x4 tyre. Tyres are the most important components of the off-road vehicle, which are crucial for progress, driving pleasure and your safety.
The choice of the right tyres has a much more significant influence on the driving behaviour of the off-road vehicle than on a car.
For off-road vehicles with four-wheel drive, it is advisable to change all four tyres at the same time, so that all wheels have the same circumference. Otherwise, it can lead to severe transmission damage due to different gear ratios.
The right size
The dimensions of a tyre depend on the size of the rim and wheel arch.
The tyre size can be found on the registration certificate of your vehicle. Noted are the cross-section, the tyre height and the diameter.
For every application, it needs a suitable tyre. The selection criterion is the terrain in which you are travelling: normal roads, sand, rock, grass, fields, mud and/or tarred roads, summer or winter in mud terrain or all-terrain. The percentage of asphalt road and terrain, as well as the profile shaping, are decisive.
It is divided into the following types of tyres:
- Street Terrain (ST): safe, comfortable driving on paved roads and paved paths.
- All-Terrain (AT): mixed-use, on tarred roads and easy to drive terrain.
- Mud terrain (MT): predominantly difficult terrain, wet ground, such as mud or rubble and sand.
- Winter tyres (M + S): for wintry and icy road conditions.
- Special tyres: for 100% off-road use in motorsport in the most difficult terrain; for Cross, Trial, Mud Bogging, Rock Crawling, Trophy.
The perfect tyre for all roads and all conditions does not exist. An all-terrain tyre is a good compromise. But in demanding off-road use, it quickly reaches its limits. A pure off-road tyre, however, is very treacherous on the tarred road. It should be driven “on road” only conditionally and with caution. We, therefore, recommend having two complete sets of tyres.
More tips for off-road tyres
A false air pressure is the most common cause of tyre failure. For example, the tyre heats up when the air pressure is too low and can be severely damaged by the resulting heat inside.
This can even lead to the tyre bursting at high speeds. If a tyre is damaged, this cannot be corrected by subsequently correctly adjusted air pressure. In addition, too low or too high air pressure increases the tyre wear disproportionately.
When driving off-road, the air pressure can be lowered to increase traction. After an off-road ride, however, it is very important to re-inflate the tyre to the correct inflation pressure. Use a manometer for lowering and then refilling. Guesswork has already led to many surprises!
- In moderate terrain on the wet or dry ground, a 10% reduction is recommended.
- In the mud, water or snow, even more, air can be drained. This should not be more than 30%.
- In the sand, you can reduce the tyre pressure to 25 – 40%.
A reduction of 50% and more should generally be avoided. The traction deteriorates greatly, and the tyre is exposed to extreme stress.
For vehicles with permanent four-wheel drive, the air pressure must be adjusted so that the tyre circumference is the same at the rear and the front so that there are no gear disagreements.
This facilitates the shifting of the central differential, significantly reduces fuel consumption, mechanical wear and noise emission.
Construction of a 4×4 tyre
A 4×4 tyre does not differ in structure from a normal car tyre. In today’s standard vehicle tyres, the following construction elements are distinguished:
The tyre bead has the task to ensure the tightness of the tyre on the rim. To exclude a change in length of the tyre on the rim circumference, several wire cores are incorporated in the bead. In tubeless tyres, the tyre bead also seals the trapped air volume against the environment.
The carcass, stretched by the internal pressure, forms the supporting framework of a tyre. It consists of several fabric pads that are embedded in rubber without mutual contact. Kord, rayon, polyamide fibres and steel are used as fabric materials. The carcass strength is determined by the number of fabric documents and indicated by the PR number (abbreviation for ply rating), which does not have to correspond to the actual number of layers.
The sidewall with rubbing strips is designed as a rubber cover of the carcass from the bead to the tread and is designed to protect the fabric layers from destruction by external influences.
The tread surrounds the carcass on its outer circumference and establishes the non-positive or positive connection between the road and the tyre.