Chamber of horrors | What the law requires | Minimum tread depth | Run-flat and temporary use spare tyres |
Tyre care | Tyre maintenance check list | Tyre care on the road
Tyre care | Tyre maintenance check list | Tyre care on the road
| Km/h | Load capacity supplement (%) | Inflation pressure increase (bar) |
| 60 | +10 | +0.1 |
| 50 | +15 | +0.2 |
| 40 | +25 | +0.3 |
| 30 | +35 | +0.4 |
| 20 | +42 | +0.5 |
General advice on inflation pressure
On-road
The given maximum load capacities with corresponding inflation pressure are valid up to a speed of 160 km/h (speed index Q). With higher vehicle related V-max and driving faster than 160 km/h the inflation pressure has to be increased to assure the same load capacity respectively the load capacity of the tyre must not be fully used to 100%. As a rule each 10 km/h speed increase requires higher inflation pressure by 0.1 bar (see table).
For definite Information about inflation pressure and load capacity above 160 km/h please contact our customer service department.
Off-road
It is recommended in certain situations with slow off-road driving to reduce inflation pressure. This will enlarge and widen the ground contact area and improves traction by increased dovetailing of the pattern with the ground.- Sinking and digging in on soft surfaces will be reduced.
- In addition the tyre becomes more flexible so sharp-edged stones and other obstacles can be passed at lower risk of damage.
- The increased flexibility also results in improved self-cleaning of the pattern on mud and snow.
- On sand also lower inflation pressure is recommended as the larger contact patch will improve traction.
The inflation pressure must never fall short of 50% of the nominal pressure or below 1.2 bar and the speed must not exceed 80 km/h. On returning onto normal roads the standard inflation pressure has to be re-adjusted as higher speed will be achieved again.
When driving with reduced inflation pressure at high speed the tyre is heating up extensively due to increased internal movement. Structural damages and loss of tyre could be the result. These consequences can also occur much later when an initial correlation with driving at insufficient inflation pressure cannot be expected anymore.
| Surface Conditions | Inflation pressure reduction* |
| On-road inflation pressure: | Always keep as vehicle manufacturer's manual to avoid serious prejudice on safety, premature wear, excessive heat generation and vehicle performance loss. |
| Off-road inflation pressure: | |
| Rough terrain | -10% |
| Sand | -25 - 40% |
| Mud | -30% |
| Loose ground at very low speed/short distances | Up to -50% |
| *Always re-inflate tyres after returning onto paved roads |
Tyres with LT marking
If the off-road tyres have LT marking (LT = Light Truck), increase in load capacity is possible without increasing inflation pressure as LT tyres usually have a higher level of inflation.
| LT-Tyres with load Index up to 121 and speed Index of Q (180 Km/h) to T (190 Km/h) | |
| Km/h | Load capacity supplement |
| 80 | +10 |
| 70 | +12.5 |
| 60 | +15 |
| 50 | +20 |
| 40 | +25 |
| 30 | +35 |
| 20 | +50 |
| 10 | +75 |
Further important tips for off-road driving
General advice
Proper preparation makes for a successful off-road trip.- Make sure your tyres are in top condition before you start your off-road tour.
- Don't forget to check the spare wheel.
- Carry an electrical or manual air compressor (with a pressure gauge) with you to be able to adjust inflation pressure according to the ground conditions.
- Always wear safety belts even at low speeds. Any loose objects that you carry in the car should be fixed in position.
- Due to the heavier weight of a 4x4 vehicle, the braking distance is much longer than with a normal passenger car.
- In difficult conditions, air conditioning should be switched off as it can use up to 10% of the engine power.
Driving on soft ground
- In the case of soft or loose ground a larger contact patch is better than higher ground clearance.
- When slowly traversing difficult areas of soft ground, try to keep your vehicle in motion. Once stopped it will be far more difficult to get it going again. If you are stuck, do not spin the wheels, as you will only dig in until the vehicle chassis rests on the ground. Try to go slowly backwards in your own tracks, as these have been compressed by your vehicle previously. In most cases this will be more successful. If not, place appropriate material (wooden planks, mats, branches etc.) under the wheels to improve grip.
Driving on rocky ground
- On rocky ground, or ground with many obstacles and climbs, a high ground clearance is preferred (narrower, high tyre profile).
Driving on slopes
- Difficult terrain should first be inspected on foot.
- On descents, vehicles with diesel engines are easier to control than other engines due to the stronger engine braking capabilities.
- Always use the 4 wheel drive when driving on steep slopes. Always switch on the 4 wheel drive before you leave paved roads and enter off-road terrain.
- Always approach steep ascents and descents in a direct line. No change of gear will be possible once you are on the slope so begin in the appropriate gear. Never slip the clutch.
- Never attempt to go down a steep slope if you are not sure you can make it back up again if necessary.
- Drive at right angles to the slope if possible. If a sidewards incline becomes too steep and the vehicle tends to tip over, steer downwards and accelerate slightly until the vehicle is under control again.
- Never slip the clutch on steep ascents or steep descents as the vehicle can easily slip away.
- Always take into account the maximum ramp-over angle of your vehicle.
- In difficult terrain keep the sunroof and windows closed to avoid injury to your head or arms, should the vehicle tip over.
- When driving difficult routes in convoy, only enter severe passages when the vehicle in front of you has cleared them completely.
Passing obstacles
- Don't straddle large obstacles between your wheels, drive over them with the tyres (lower risk of grounding the gearbox, differential or vehicle floor).
- Deep track marks should be taken between the wheels to avoid the differential touching the ground. Do not force the steering to leave the tracks, let it turn freely.
- Ditches and embankments should be approached in a diagonal line to make sure that at least 3 wheels have ground contact all the time. Steer straight until the obstacle has been passed.
Driving through water
- When driving through water always consider the maximum wading depth of your vehicle. The air intake must always be kept clear of water. Driving through water should always be done slowly to keep the bow wave low. In addition, slow speed prevents a hot engine suffering tension cracks by sudden contact with cold water. Check the brakes after leaving the water.
