HAVING COMPLETED the transition of the Massey Ferguson 7400 Dyna-VT and higher horsepower models in the 6400 Dyna-6 ranges into the combined 7600 Series spanning 140hp to 280hp, attention has now turned to revitalising the four-cylinder models with the MF 6600 Series.

With power outputs currently starting at 120hp and climbing to 185hp with pto/transport power boost engaged, this new line-up contains the most powerful four-cylinder tractor in the market and a choice of three different transmissions.

"The MF 6600 Series has developed for the new generation of farmers who are looking closely at their asset management in terms of labour, power, soil protection, cropping and the environment," says Campbell Scott, MF's brand development manager. "It combines the right size and power with productive features that are needed to farm most effectively in today's challenging conditions."

The tractors are said to offer users the power, torque and operating benefits associated with a six-cylinder tractor in a more compact four-cylinder format, providing great agility and power-to-weight ratio.

They fit between the new MF 5600 Series spanning 85-105hp using three-cylinder engines and the six-pot MF 7600 line-up with a high level of standard specification and choice of transmissions, hydraulic systems and cab comfort.

As well as sharing a cab of similar size and style as the unit fitted to the six-cylinder tractors, the MF 6600 Series tractors share their Dyna-4 and Dyna-6 semi-powershift and Dyna-VT stepless transmissions in a choice of Essential, Efficient or Exclusive specification packages. All told, there are 10 different variants.

Tractor aficionados who pride themselves on accurately recalling the power outputs of individual tractor models have more of a challenge on their hands with these MF tractors because machines with the same model number but different transmissions do not have the same outputs – or spec options, for that matter.

For example, the MF 6615 with Dyna-4 drive has 145hp for draft work and 160hp for pto and transport operations, and is available only with the base Essential spec – although individual features from the other packages can often be added as options.

With Dyna-6 installed, this model has 150hp and 175hp outputs, and all three spec packages, while the Dyna-VT version has 150hp for all activities – there is no added boost feature.

To keep exhaust gas and particulate emissions within the latest limits, the tractors have selective catalytic reduction (SCR) and a diesel oxidation catalyst (DOC) on the 4.9-litre four-cylinder AGCO Power (Sisu) engine.

This requires a supply of urea solution to inject into the exhaust stream but does mean that the combustion process can be tuned for efficient generation of power and torque, which pays off in terms of fuel use efficiency. The catalysts and slip cats are housed in a slim, oval-shaped exhaust pipe.

With a relatively short overall length but generous 2.67m wheelbase, the tractors are said to combine good manoeuvrability in small fields and the tight confines of a farm yard with positive stability and traction.

To maintain this concept when front-mounted implements are used, a new front axle support casting allows a 3.2 tonne capacity front linkage and pto assembly to be installed within minimal additional length. It also caters for front axle suspension and a hydraulic loader.

Operators who like the idea of a little less arm twirling at headlands and when using a loader can have SpeedSteer installed, which reduces the number of steering wheel turns needed to go from lock to lock.

Other driving aids include Dynamic Tractor Management (Dyna-TM), which automatically adjusts the engine speed according to load on stepless drive Dyna-VT tractors, and AutoDrive for the semi-powershift tractors, which is available for the Dyna-4 transmission for the first time in addition to the Dyna-6 Eco transmission.

In the 'Hare' setting, intended mainly for road use, AutoDrive automatically changes Dynashift speeds and ranges through 16 ratios in all. For fieldwork, 'Tortoise' setting restricts auto operation to the four or six powershift steps within each range.

Also, bringing the tractor to a halt using the brake pedal will automatically activate the transmission clutch. Releasing the pedal engages the clutch once, which means it can be driven off simply by building engine revs – a handy feature for repetitive loader work, suggests Campbell Scott at MF.

AutoGuide steering and AGCOmmand data telematics are also available on the new tractors for farmers who want to exploit the latest electronics technology.