Outwardly, the latest-spec high horsepower models in the Deutz-Fahr stable share much of their dynamic appearance with preceding versions.

While the Deutz engines are already equipped and tuned to meet European Stage V emissions rules, under the cab there is a new continuously variable transmission (CVT) said to be more efficient and more user-friendly than the one installed before.

The TTV models in question are the 192hp 6190 and 216hp 6210, and the 230hp 6230 that comes in ‘regular’ and ‘HD’ variants; and the 247hp 7250 and 7250 HD.

These six-cylinder tractors are aimed at large arable units, as well as sizeable grassland farms and contractors. Notable features include Dana suspension front axles with 600mm external dry brake discs for optimum braking effect – they account for up to 60% of the braking force; 90 litres of hydraulic oil trailer tipping capacity from a supply that is separate from the transmission; and 50kph or 60kph gearing to allow road runs at reduced engine speeds for fuel economy gains.

Running costs are also helped by the 1000-hour oil and filter change intervals for the Deutz 6.1-litre TCD engines, and the corresponding 2000-hour service interval for the new CVT transmission.

The layout and components used are upscaled in four versions to suit different power outputs, controlled by SDF’s own software and installed with new SDF rear axles at the Deutz-Fahr factory in Germany.

SDF already makes its own CVT for smaller tractors and decided to adopt the higher-power unit when ZF announced it would cease production of the S-Matic transmission used in previous Deutz-Fahr tractors of equivalent power.

The S-Matic is a four-range design with variable speed regulation in each range and automatic range shifting, with hydrostatic propulsion contributing only a modest proportion of drive at any time.

This contrasts with the AGCO AVT transmission – better known as Fendt Vario – which transitions from 100% hydrostatic to 100% mechanical drive in a linear trend, with manual range selection for field work and road travel.

Read more: Deutz-Fahr adds highly-connected 7-series units

The Deutz-Fahr unit is also a two-range transmission but with auto shifting between the two – requiring no conscious input from the operator – and two hydrostats working in conjunction with an epicyclic gear unit.

Reverse travel is fully hydrostatic and in forwards motion there is linear progression from 100% to virtually zero hydrostatic drive across a relatively narrow ground speed range, hitting 50:50 at around 7kph.

The high proportion of hydrostatic drive is said to deliver smooth and progressive control for low-speed manoeuvres such as headland turns and when working with a loader, and fine speed adjustment when operating a harvester or stone/clod separator.

However, when the transmission auto shifts to the second range – which does not occur at a set speed but at 8-16kph according to a combination of engine revs and load – drive becomes largely mechanical, with never more than 30% hydrostatic propulsion, and 100% mechanical at the change-over point and at top speed.