26 June 1998

Small but full of poke

Fendts user friendly and

power efficient Vario

transmission has recently

been introduced on lower

powered 900-series tractors.

Geoff Ashcroft went to

Germany to see how the

smallest model, the 170hp

916 Vario performs

WITH 260hp, one could be forgiven for thinking that the first Fendt Vario tractor – with its hydro-mechanical transmission – could afford to lose a few horses through the transmission without anyone really noticing.

And so it follows then, that any lower powered models could only suffer greater transmission losses and ultimately could prove leviathans. Not so.

Fendt, it seems, has done its homework with the Vario, which achieves a transmission efficiency of 82%, and fitted to the 170hp 916, feels every bit as inspiring to drive as the range-topping 260hp machine.

No power sapping transmission, the Vario combines hydraulic and mechanical drives in two speed ranges to provide a stepless drive in two ranges – 0-20mph and 0-31mph. Fendts theory is simple; pick the speed you want (instead of selecting gears) and use the engine power as required to achieve maximum output.

Vario takes the drive from the engine into a planetary unit where drive is split in two – a hydrostatic section (the ring gear) drives an axial piston pump while the other half of the drive, the mechanical section (the sun wheel) is connected to the rear axle shaft and the transmissions range selection.

Infinite variation of gear ratios is controlled through the adjustment of the hydrostatic pump and motors, with the proportion of hydrostatic drive to mechanical drive changing in respect of engine speed, forward speed and workload.

Physically, the 916 differs little when compared to its more powerful stablemates. With the model badges removed, it would take a keen operator to notice the differences in performance when driven without an implement hooked to the rear.

Engine output, rear axle strength and wheel/tyre equipment are the major differences, and are responsible for the 916s slightly lighter operating weight of 7.7t against the 8t flagship 926 model.

Using the same cab as other Vario models poses no restriction on operator access to the cab of the 916. Inside, the tractors reverse drive console creates a light obstruction in what would otherwise be a flat-floor cab.

As for driving, the 916 Vario is all about its gearbox, so this is where we will start.

Once seated, the armrest greets you with a short joystick control, it is the nearest resemblance to a gear lever you will find in the Fendts roomy cab and is flanked by push buttons for neutral and speed range selection.

Two safety features need to be overcome before the transmission will work. The first requires the neutral button to be pressed to first activate the box, then thumb the top switch on the joystick while moving the lever forward and the tractor moves off.

Moving the lever further increases speed, while pulling the lever back slows the tractor.

Changing direction requires the stick to be pulled to the left while pressing the button on top of the joystick – and repeating the process changes direction again – with confirmation of the direction selected shown on the dashboard.

When in reverse, joystick fore/aft movements are also reversed and means pulling the stick back now increases speed, while pushing forward decreases speed.

Add to this the ability to change the rate of how the transmission responds to joystick movements (via a four-position switch on the front of the joystick) and the big picture starts to unfold. The Fendt Vario is all about maximum productivity.

Some operators will find the driving experience a little unnerving at first. Driving by wire and oil is a complete break from the traditional pick-a-gear-and-open-the-throttle approach, and is one which needs a certain amount of adjusting to, and a degree of concentration from the seat.

But with time, the 916 Vario has the potential to be operated smoother and more progressively than its powershift-equipped rivals. And even with 170hp, the efficiency of the transmission gives the feeling that the tractor is in no way under-powered.

FENDT 916 VARIO

&#8226 Engine 170hp MAN six-cylinder turbocharged and intercooled

&#8226 Transmission Vario stepless transmission; field range 0-20mph, road range 0-31mph

&#8226 Hydraulic lift 9.1t

&#8226 Weight 7.7t

&#8226 List price £85,640

Above: At 170hp Fendt 916 is the lowest powered Vario model, but transmission efficiency makes the tractor feel more than adequately powered.

Right: The key to it all… a short stubby joystick on the armrest is responsible for the transmissions operation.