Case IH has added to its heavy-duty Optum tractor line-up with a trio of higher horsepower models that top out at 435hp.

This substantial hike puts them on an equal power footing with the larger Magnums, albeit in a more compact platform that can be used for a broader range of tasks.

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Unsurprisingly, they employ the same 8.7-litre FPT Cursor 9 engine, which offers considerably more capacity than the 6.7-litre unit used in smaller Optums.

That said, they are fitted with a structural sump rather than sitting in a separate chassis, in a bid to improve manoeuvrability.

As for the CVX stepless transmission, this has been toughened up to handle the additional strain. Yet it retains the four-range configuration to give a decent proportion of mechanical drive.

In line with Case IH’s policy of badging tractors with their rated power, the smallest and mid-range Optum 360 and 390 deliver precisely as advertised.

And, due to a particularly flat power curve, rated and max outputs are the same.

Only the flagship 440 bucks this trend, delivering a slightly lower 335hp than the stickers would lead you to believe.

When fitted in the Magnum, the Cursor 9 has a 500-hour service interval, but engineers have managed to stretch this to 750 hours in the Optum, matching up with the rest of the range.

Redesigned running gear

More changes have taken place in the drivetrain department.

There is a stronger axle at the rear and a new unit at the front, featuring double wishbones and self-levelling hydraulic dampers with 250mm of travel.

This is built in-house, with inboard brakes sitting in oil that’s shared with the backend. As a result, there’s only one fluid to change and it’s properly cooled as it passes around the system.

Together with careful shaping of the front castings, the new axle gives the large Optums a tighter turning circle than the small ones, at 12.2m.

Other perks of the running gear upgrade include a 60kph top speed and the option of factory fitted central tyre inflation, which can be controlled from the tractor screen.

This offers two in-field presets and a road setting that allows operators to quickly get tyres to the desired pressure.

Making adjustments of 1 bar will take about five minutes, although most operations will require a smaller fluctuation than this.

Designers have also put some efforts into the design of the wheel weights, by adding cones that help them locate more easily on the hubs.

Cab and controls

Other than some suspension tweaks, the cab is unchanged – understandable given that it has only recently been treated to a significant overhaul.

Nevertheless, there are now staircase-like “walk-in” steps, as well as an integrated toolbox and a built-in water tank for washing hands.

Updates are plentiful at the back, where rear lift capacity has been bumped up to 11,760kg and there’s the option of either a single or twin hydraulic pump setup.

Output from the standard assembly is 220 litres/min, with the dual configuration pushing flow to 360 litres/min.

Helpfully, these supply separate sides of the spool block, allowing operators to set priority flows for two services.

For example, the regular pump can be asked to give first dibs to the link arms when running a large mounted drill, while the second concentrates on feeding the fan.

Production of the big Optums will take place at CNH’s factory in St Valentin, Austria, extending the range to a total of six models running from 270 to 435hp.

New Holland versions are also coming, full details of which will be revealed at the Agritechnica event in Germany this November.

These will be easily distinguished from the current T7 HD as they will feature T7 XD branding.