- Winter tires are more efficient under 6-7 °C. The wearing of a winter tire in summer will be quit high.
- Tire too old

- Brittle rubber
- Corrosion on valve core
- External damage

- Unsafe handling up to loosing control
- Extended braking distance
- Higher fuel consumption
- Higher rolling resistance
- Increased tyre wear

Torque is not a standardized measuring and you cannot compare the data of different manufactures, because of different measuring processes and equipment. There is no aligned measuring procedure like impact energy for rotary hammers, where the EPTA (European Power Tools Association) defined.

- Dimension of the hose
- Coupling
- Impact wrench itself
- Air-Pressure (Recommended 6,3 bar at the tool)
- Lengths of hose
- Oiled pneumatic air
- Power of the compressor

The fan-blades have a higher wearing which effects a shorter life time of the product

An imbalance of a wheel occurs when the axis of rotation does not correspond to one of the mass centroid axes. Poorly-balanced wheels can generate a critical condition on the vehicle:
- The steering vibrates
- More stress on wheel suspension and bearings
- More noticeable vibrations in the interior
- Physical strain on the body increases
- Increased brake wear can result
- Increased tire wear can result
- Extension of the braking distance may be the result

There are two types of imbalances - static and dynamic imbalance.

Static imbalance:
If there is a static imbalance, the spot on the wheel with the greatest mass is acted upon by gravity to deflect the wheel downward. Static imbalance always occurs in the center of the wheel and causes it to bounce while driving. The static imbalance can be compensated by applying wheel balance weights on the opposite side of the occurred imbalance.

Dynamic imbalance:
Dynamic imbalance is caused by an asymmetric mass distribution inside and/or outside of the rim. The asymmetric mass distribution is only visible during movement when the forces work in different directions and cause the wheel to hop or wobble. To determine a dynamic imbalance the tire/wheel assemblies can be checked on a balancing machine. The dynamic imbalance can be compensated by applying wheel balance weights on the outer and inner side of the rim.

At a speed of 100 km/h, the centrifugal force of a 10 g imbalance is equal to that of a sledge hammer. Double this speed and the forces involved quadruple. Vehicles with poorly balanced wheels become dangerous:
- More stress on wheel suspension components and bearing points
- Noticeable vibrations on the steering wheel and in the interior
- Body subjected to greater physical stress
- Increased brake wear
- Increased heel and toe wear on tyres
- Braking distance increases

An imbalance has a significant effect on the vehicle. The effects are seen in three areas:
- comfort,
- safety and
- wear.

Strong vibrations at the steering wheel and inside the vehicle, along with constant humming noises are the first signs of an imbalance.
After 2,000 km of driving, significant uneven tyre wear is detected on all four wheels. Early repairs may be necessary due to increased wear at the suspension arms, shock absorbers and bearings. In the braking test, the braking distance of the test Golf moving at a speed of 140 km/h increased by 6 mtr. This can be decisive in case of an emergency situation.

- Safety reasons
- No damage of the rim
- No damage of the thread and bolt
- On road repair is possible (opening torque will be not too high)
- Warranty reasons

It is to ensure the accuracy of the torque setting. Because of the sensitive mechanic and wearing there could be larger tolerances and of course the torque wrench should deliver reliable results.

There are too much influences of the power of an impact wrench, like lengths of a hose, dimension of hose, air pressure, weight of the socket, etc.