VarioGrip for the right pressure in the tyre

The integral tyre pressure regulation system VarioGrip adapts the tyre pressure from 0.6 to 2.5 bar within the shortest amount time – even while driving. This is accomplished on all wheels via the integral rotary union, which is designed to last the lifetime of the tractor. Air is supplied via a water-cooled double-compressor as well as the vehicle's own valve equipment.

Up to 8 percent lower diesel consumption in the field

Up to 2 percent lower diesel consumption on the road

Up to 8 percent more area coverage in the same amount of time

The right inner tyre pressure delivers more force to the ground and therefore more pulling power. Adjusted inner tyre pressure effectively reduces slip and rolling resistance. And that has a positive effect on area coverage. If the high inner tyre pressure is reduced during heavy-duty cultivating work, the tyre’s ground contact automatically increases. This reduces slip and increases efficiency, which means up to eight percent more area is covered in the same amount of time.

At 500 hours of heavy-duty draft work per year, this means up to 40 hours less working time. Calculated per operating hour, this results in a higher area coverage and at the same time reduces diesel consumption for savings of up to 10 €/hr*. Assuming the tractor is used for heavy-duty draft work half of the time, this amounts to a 50,000 € savings potential in 10,000 operating hours.**

* South Westphalia University of Applied Sciences, Agriculture Soest
** Based on 10,000 hrs, 50% draft work, 5,000 hrs x 10 €

Up to 3 percent faster on the road with the same engine power

Up to 50,000 € saved through Fendt VarioGrip

Up to 3% faster

An inner tyre pressure of 2.4 bar instead of the usual 1.8 bar on the road shortens driving time by up to three percent, while consuming two percent less diesel.

2.4 bar inner tyre pressure on the road means:

3% shorter driving times
2% less diesel

Up to 8% more area coverage

During tillage, the optimal tyre pressure of 0.8 bar, instead of the usual 1.8 bar, can increase draft performance by ten percent. This increases area coverage by eight percent while reducing diesel consumption by eight percent per hectare. For 500 hours of heavy-duty draft work per year, this means 40 hours less working time.

0.8 bar inner tyre pressure means:

10% more pulling power +
8% more area +
8% less diesel +
40 hours saved per 500 hours of operation

Up to 10 €/hr saved

Per operating hour, this results in savings of 10 €/hr for heavy-duty draft work. In 10,000 operating hours, of which 50 percent is for draft work (i.e. 5,000 operating hours), 50,000 €** can therefore be saved.

0.8 bar inner tyre pressure means:

10 € per hour saved
50,000 € saved in 5,000 hours of draft work

* South Westphalia University of Applied Sciences, Agriculture Soest
** Based on 10,000 hrs, 50% draft work, 5,000 hrs x 10 €

VarioGrip protects the soil and enables high yields

Less soil compaction

In farming, lower soil compaction is generally achieved by reducing the contact area pressure. Less air pressure in the tyre means more contact area. The load is therefore distributed over a larger area.

Less soil compaction
In farming, lower soil compaction is generally achieved by reducing the contact area pressure. Less air pressure in the tyre means more contact area. The load is therefore distributed over a larger area.
Higher soil fertility
The right inner tyre pressure increases efficiency and enables gentle transfer of the tractor’s power to the ground. This results in improved soil fertility and higher yield.
Fertile soil
Air and water are stored in pores in the soil. A fertile soil is characterised by around 40 percent open pores and 60 percent solid substance.* The latter carries the entire weight during cultivation work. An adjusted air pressure contributes to the structure and maintenance of the pores.
* Source: Prof. Dr. Volk, University of Applied Sciences Soest

Distribution of ground pressure

Well known and time-tested: An adapted, lowered inner tyre pressure not only increases area coverage and lowers diesel consumption, but also effectively protects the soil. A softer, wider tyre increases the ground contract area, so weight is distributed better, which in turn lowers the ground pressure. If the tyre is narrow and hard, normal soil is unnecessarily compacted. The surface is also damaged by the “slip with cutting effect” *caused by the tyre tread, and more fuel is consumed: tracks with a depth of more than ten centimetres double the fuel consumption*.

* Source: Prof. Dr. Volk, University of Applied Sciences Soest

Leave the right track behind

The image shows the impression of the same arable tractor tyre, once with a high (right) and once with a low inner tyre pressure (left). One can recognise the effect air pressure has on the soil by the length of the tyre impression. The right-hand image shows the impression of the tyre with high pressure. It clearly shows a shorter contact area. The weight is not as well distributed, so the tyres sink deeper into the ground. The left-hand image shows the same tyre, but this time with low air pressure. The tyre can expand and weight is distributed better on the ground. The contact area is considerably longer and wider, so there is less pressure on the soil.

Perfectly integrated - Simple operation via the Varioterminal

Using the Varioterminal, the tyre pressure of the tractor can be controlled with just a push of a button. The assistance system informs drivers about too low or too high tyre pressure.

Tyre pressure regulation system: The technology

VarioGrip is the fully integrated Fendt tyre pressure regulation system that uses the vehicle’s own valve technology and routing of air flow. The complete solution is based on a water-cooled high-output compressor with two pistons, which ensures a very high-volume air current. Radial rotary unions are found on the front and rear axle. In this two-line technology, the control line opens the tyre valve; the tyre pressure is increased and decreased via the fill line. The rotary unions are subject to low wear, since they are only under pressure when increasing or releasing pressure.

A further advantage is that no air can escape from the tyres when the lines are damaged, which means higher safety. The system is easy to control from the Varioterminal: The inner tyre pressure for the front and rear axles can each be adjusted separately for field work and on-road driving. These settings are stored in the Varioterminal. In this way, the tyre pressure regulation system also permits pressure control while driving.

Intelligent integration on the front axle

The lines for the VarioGrip tyre pressure regulation system run through a radial rotary union. The valve on the tyre is opened pneumatically via the control line (green). The air pressure in the tyre can be lowered or increased quickly via the air line (blue).

Filling line to valve

Control line to valve

Filling line - inlet on steering knuckle

Control line - inlet on steering knuckle

Radial rotary union front axle

The tyre pressure regulation system in neutral test

The proof

A neutral study of the University of Applied Sciences, Agrarwirtschaft Soest impressively proves that the VarioGrip integral tyre pressure regulation system boosts efficiency. The study was carried out in August 2014 with a Fendt 828 Vario equipped with the integral tyre pressure regulation system VarioGrip. Both the effects during heavy-duty draft work in the field as well as during transport trips were determined. The results of the study show clear economic benefits that pay off.

As a basis for calculating slip, the tyre circumference was determined on solid ground with different air pressures.

A pulse counter was attached to the axle funnel to ensure as exact a recording of the tyre rotations as possible, in order to determine the theoretical speed.

To measure fuel consumption during the VarioGrip test, an external volume counter was installed in the diesel feed and return.

Tyre pressure regulation system – because it pays off!

Depending on the operation, it may be necessary to adapt the inner tyre pressure often. The integrated tyre pressure regulation system VarioGrip, which adapts the inner pressure while driving, therefore saves a lot of time. Thanks to VarioGrip, the time required for adjusting the inner tyre pressure when driving and leaving the field is reduced to a minimum and work is completed faster.