The many variants of the "utility" range
Most of the power band of the tractors known as "wildcard" or "utility", is around 75 kW. They are means designed to offer maximum operating versatility, and to be able to adapt to the most different working situations. These tractors offer a broad range of variability in terms of possible configurations, both for the driving position, as for the engines, the transmissions, and the hydraulic systems, as well as for the axles and the braking systems
A recent analysis carried out by professor Luigi Sartori of the University of Padua has shown that in Italy there are 1,600.000 tractors operating (the estimates on the existing park indicate in theory a total number of more than 2 million units, editor’s note). This is the reason why the country appears to be the third in the world for the number of agricultural tractors in the area, but given its small arable area, it is also one of those with the lowest surfaces in the world worked by each tractor, equal to only 4 hectares. All this does not happen by chance, the availability of vehicles is high also because Italy is the world’s third largest tractors and agricultural machinery manufacturer, being this Italian sector a solid industrial sector appreciated all over the world, with over 80% (and for some companies over 90%) of the production exported (and appreciated) all over the globe. In his detailed analysis, Professor Sartori has also estimated that the average age of our tractor fleet is very advanced, equal to about 20 years, and explained this value with the fact that tractors, having to operate for a few hours a year, end up having limited wear and therefore a particularly high duration. However, it is also important to consider that the average power of tractors sold on the Italian market has risen from 45 kW (61 Hp) to 75 kW (102 Hp) with an increase of more than 60%. Most of the tractors defined as “wildcard” or “utility” power band are around 75 kW. These kinds of tractors are designed to offer the maximum versatility of use and to be able to adapt to the most varied working situations. Many experts define them as tractors of class 4 or class 5, referring to the names taken from the numbers that manufacturers commonly use today on the bonnet of these machines.
In addition to representing the average power of the tractors sold, it is important to note that most of the tractors registered have around this power value. The range of power ranging from 80 to 120 Hp (from 58.8 to 88.23 kW) has, in fact, the most interesting in numbers as far as sales are concerned (verify FederUnacoma statistical data), and it is also the one in which there is the widest variability in terms of possible configurations, both for the driving position, for the engines, for the transmissions and the hydraulic systems, as well as for axles and braking systems.
Driving stations
Starting from the differentiation in terms of driving positions, this category of machines offers the higher possible variability. In fact, both cab tractors and tractors only equipped with the two rear-mounted overturn protection device are marketed, a device that sometimes is offered with the type that provides for partial folding and sometimes it comes with a comfortable sunroof. Rarely, machines equipped only with two front-mounted rollbars totally foldable. Whilst, for machines equipped with a cab, the range goes from classic cabs with six uprights to the most modern ones with four uprights, which offer a better side view. Whereas, as regard attaching the cab there are solutions that imply that the cabs are anchored to the tractor wagon by interposing silent-blocks of different types (and effectiveness), and solutions that provide the most effective passive suspension of the cab (usually equipped with the “spring and shock absorber” system). In some cases there are even optional solutions derived from high power tractors that provide hydropneumatic suspension, often also equipped with a semi-active control of vibration damping, to offer the best comfort to the driver.
Engines
In terms of engines in this power range there are several and varied options. First of all, it should be noted that the classic six-cylinder engines, which 20-30 years ago were for the 100-120 Hp tractors in both the inlet and the turbocharged version, have now been effectively supplanted by the four-cylinder architecture with turbocharger and intercooler, as well as with all those technical solutions that have in the meantime become necessary to comply with the dictates of the anti-pollution regulations.
Among these, we need to mention the direct injection with electronic control (often with the common-rail scheme), the exhaust after-treatment devices such as the oxidizing catalyst DOC and the selective catalytic reduction with SCR urea fed.
In some cases, there are also different types of particulate filters, as well as internal or external exhaust gas recirculation systems, which in this last case require the recirculating gases are cooled and their quantity modulated by an electronically controlled actuator according to the different operating requirements. It is also interesting to note how, in this power range, the three-cylinder engines are also appearing, especially favored by those who want to maximize the machine maneuverability (for example to be used in the stable), given that with a less fractioned engine it is possible to obtain a reduction of the pitch of 10-15 cm.
Transmissions
In the transmissions field as well, the configuration variability implemented by the different manufacturers is extremely wide. In fact, it is possible to find on the market tractors equipped with simple (and very efficient) essentially mechanical transmissions, with dry friction equipped with four or five gears for two ranges and mechanical reverse shuttle, and other solutions with the implementation, on the same basis, of two or three ratios in powershift and of the hydraulic reverse shuttle, with the addition of one or two ranges to achieve even super-reduced ratios. For those who have even more specific needs, many manufacturers envisage the possibility of using, in this power range, even the most recent continuous variation transmissions (CVT), based on the concept of the mechanical-hydraulic branching of power (split-power), which, even if suffering from obtaining, sometimes, rather low-performance levels in certain situations, they have the advantage of offering a much better ride comfort compared to mechanical transmissions. There is also a wide choice of power takeoff’s transmissions. It is rare, nowadays, to find among the utility tractors machines that offer only the classic mode of operation at 540 rpm, normally (and luckily) this mode is accompanied by at least from 1000 rpm or from 540 Eco (also called 750 rpm) mode operation. Finally, there are also cases of machines that offer even all four existing operating modes (ie both 540 and 1000 rpm also available also in Echo mode). On the vast majority of the machines of this category, the power take-off synchronized with the wheels, and the front one at 1000 rpm are usually provided. In general, because of friction caused by the engagement of the p.d.p. in this power range there is a drastic decrease of the machines sold with the classic dry clutches and manual grafting, in favor of the solutions that provide wet-running clutches with electrohydraulic clutch, often modulated and with the possibility of automation of the engagement and subsequent disengagement of the movement towards the grooved tube according to the position of the hydraulic lift. Even in this power rating, solutions coming from higher-range tractors are beginning to spread more and more frequently, involving the introduction of double traction and the locking of the electrohydraulically controlled differentials, often already offered in the standard equipment.
Hydraulic systems
In this area as well, the “utility” tractors offer a high versatility of solutions proposed. The basic option is often represented by the classic open center system, with fixed displacement pumps with a maximum capacity of 55-70 l/min and two or three mechanically controlled rear distributors. The optional fittings are extremely varied and include increased pumps (always with a fixed flow rate but with capacities that sometimes exceed 100 l/min) and also solutions that extend the outfitting of rear distributors to arrive normally up to ten ways, to which it is possible to add up to two front ways. Always as an option, and for several models, it is then possible to switch to electronic control of the distributors, which is normally offered together with the option of using closed-center systems with more efficient Load-Sensing pumps, which allow the maximum flow rates of the system to grow over 120 l/min. The rear lifts have maximum lifting capacities detected near the coupling points which, on average, range from 2600 to 5500 kg. In most cases, they involve a mechanical stress control, but machines with an electronic control are also increasingly sold with lower arms of the appropriately sensed three-point coupling. On the other hand, optional front lifts have a maximum capacity of between 1200 and 2000 kg.
Axles and brakes
The most popular option is to use the classic tilting front axle, but even in this power range it is increasingly possible to opt for the installation of the most comfortable suspended front axles. As regard to the braking systems on the two-wheel drive versions, which account for at least 90% of the machines sold, the most usual option requires the presence of multiple oil-immersed disc brakes in the rear axle and the insertion of the double traction under braking. Some manufacturers, however, offer the disc brakes also on the front axle, in some cases as an option, in others already in the standard equipment. Finally, prices: given the enormous variability in terms of set-ups there is a huge variability, oscillating roughly in the price lists from values of just over 30,000 euros for an 80 Hp full-field tractor with equipment reduced to the essential, up to over 130,000 euros for a full-featured 120 Hp.
