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The usefulness of air pressure changing systems is now well known to everyone: the right tire pressure under all conditions. There are several specialists who can retrofit the tractor with an air pressure changing system. But there are also brands that can equip the tractor ex-factory with - or prepare it for - a pressure-changing system. This may be an in-house developed system or one developed in cooperation with an outside supplier. We looked at which brands can supply a tire pressure adjustment system ex-factory.

With an air pressure exchange system, you can always operate in the optimal tire pressure range of the tire. This also applies to tires with a flexible VF carcass. On the road, higher pressure leads to lower rolling resistance and high stability resulting in lower fuel consumption and less tire wear. In the field, lower pressure provides more grip (less slip), better unloading, lower rolling resistance and lower ground pressure. In the field, this allows for fuel savings of 8 to 10 percent.

Switching between field and transport pressure is usually a matter of pressing a button and the system sets the (preset) tire pressure.

Claas

Claas acquired the manufacturer R&M Landtechniksysteme (Risse & Müller) in 2017 and has had its own pressure-changing system since then. After further development, the system has now reached the next stage, where it is controlled by isobus via the tractor's terminal and has, for example, quick-release couplings on the fender, which again makes changing wheels easier.

There are two versions: the "regular" CTIC and CTIC 2800, in which an additional (hydraulically driven) screw compressor with a capacity of as much as 2,800 liters per minute is mounted on the tractor. This allows the system to get the tires to the desired pressure considerably faster than with the standard compressor. How fast? Inflating a set of 600/70R28 and 710/70R38 from 0.8 to 1.8 bar takes less than 80 seconds, according to the manufacturer. With the standard compressor, it takes about 5 minutes. Both systems can be ordered on all Arion and Axion models, although it must still be installed by the dealer before delivery. Axion 900 tractors then come "CTIC-ready" from the factory. Fitting to existing Arion and Axion models (regardless of year of manufacture) is also possible. Combined with Cemos, the tractor can also provide advice on the correct tire pressure and you can adjust it as a user.

Fendt

Fendt has now been supplying the Variogrip tire pressure control system for ten years. It is a fully integrated system with no piping outside the tire. That is also one of the biggest advantages over air pressure exchange technology that is retrofitted to a tractor. No pipes that make the tractor wider and are therefore vulnerable - before you know it, you drive them off.

Inquiries at Mechan, one of the two Dutch Fendt importers, reveal that Fendt drivers now often choose this option when ordering a tractor. About 70 percent of the newly sold Fendt 700-gen7-, 800- (the very last of which have just been delivered) and 900-Vario tractors are equipped with it. Of the top model 1000-Vario, almost every one is equipped with Variogrip. The recently introduced 600 Series is also available with Variogrip.

The air brake compressor delivers about 720 liters of air per minute. There is a two-pipe system (a control and a fill line). The air is connected to the wheel through the inside of the axles via rotating radial inlets. Thus, there are no hoses running outside. Variogrip is available on both flanged and pin axle tractors. On the 600 series, Variogrip costs 11,072 euros. For the 700 Gen7, the technology costs 16,196 euros and for the 900 and 1000 series, 19,105 euros.

John Deere

John Deere has also recently been able to provide a fully integrated pressure-changing system on its US-built 8R Series: John Deere CTIS. It was introduced in 2021 and recently became available to order on the top-of-the-line standard wheel tractors. CTIS uses the standard air brake compressor. On the rear axle, the single line runs through the thru axle, and on the front axle, the line runs through the steering knuckle and exits through the hub (a rotating radial conduit) past the final gear between two wheel bolts. Thanks to a pulse-controlled valve in the wheel, lines and seals are pressurized only during tire pressure changes.

The time required to increase tire pressure depends on the engine speed - after all, this determines the speed of the compressor. At full throttle (2,100 engine rpm), it takes 6.4 minutes to increase the pressure of four tires (front 650/65R34 and rear 710/75R42) 1 bar, according to the manufacturer. At 1,700 rpm it takes 7.7 minutes and at idle it takes 15.9 minutes. The system is controlled via the 4600 or new G5 screen at the front of the armrest. The system costs an additional 18,757 euros on a new 8R. Retrofitting the same system is not possible.

PTG

Many manufacturers do not venture into their own pressure-changing system, opting (as with front linkage and PTG systems, for example) for an external supplier. Most brands install the twin guide system from the German company PTG, which has been part of tire manufacturer Michelin for a few years. The two-pipe system works with a supply line and a control line. Only during tire pressure changes are the swivel joints under pressure. At the front and rear axles, the hoses run outside the wheels, except if the rear axle has drive axles. Thanks to a swivel grommet on the inside, the air then runs through the thru-axle and does not protrude beyond the wheels.

John Deere supplies the PTG system ex-factory on the 6R230 and 6R250 for $15,918. McCormick from tractor maker Argo Tractors can supply it on the X7 series since Agritechnica 2019 and calls the technology Easy Grip. At sister brand Landini, it is also available on the 7 Series. Massey Ferguson supplies the PTG system ex-factory on the 8S and also on the recently introduced 9S. At Valtra, it is available through the Unlimited Studio on the N-, T- and Q-series. The additional price depends heavily on the tractor and the version of the control system. On the Valtra N- and T-series, for example, it costs 10,125 euros. For the Q Series, it is 2,000 euros more expensive.

Terra Care

Steyr knocks for the pressure-changing system with the Austrian company Terra Care, which has adapted the pressure-changing system for bodywork for the Profi, Impuls, Absolut and Terrus models. The tractor is prepared for the pressure-changing system at the factory and then goes to Terra Care where the final components are built onto the tractor. Thus, the dealer has no more work to do.

By default, the system is connected to the air brake compressor. The tire pressure is set on a supplied terminal or via the isobus or S-Tech monitor. A larger compressor is available, which inflates tires up to 10 times faster than the standard compressor. Preparing the tractor costs 775 euros; the pressure-changing system itself costs an additional 6,500 to 7,500 euros.

Slow

An ex-factory system is not necessarily better than one that is retrofitted. Yes, on some brands it is fully integrated and therefore the air lines do not protrude, making it less vulnerable. But when retrofitted to a tractor with plug-in axles, the air line usually doesn't have to protrude outside either. And that only an ex-factory system would integrate nicely into the tractor terminal is a fallacy. Most manufacturers of air pressure change systems have an isobus compatible system available.

Limitations

In addition, standard systems quickly run into limitations when implemented on the air brake compressor. With frequent pumping and releasing (for example, when transporting potatoes from the field), a minute-long pumping cycle (up to 15 minutes) is not practical. Let alone if the compressor also has to inflate the tires of a tandem or tri-axle truck - if that is even possible. Low compressor capacity can be somewhat compensated for with one or more buffer tanks that are refilled in between. But it is wise to determine with the specialist before purchase whether the original compressor has sufficient capacity or whether investing in a larger (external) compressor makes sense.

Integration into the display

Although a proprietary, ex-factory system often integrates better with the screen, a retrofitted system can usually also be integrated into the screen thanks to isobus.

Claas CTIC 2800

Claas optionally mounts a hefty compressor that delivers as much as 2,800 liters per minute. It demands 90 l/min via load sensing.

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