As the first tractor over 500hp with a stepless CVT gearbox, Claas’ new Xerion might appear to be a specialist machine, but the German manufacturer wants to challenge that perception, punting its 4500 and 5000 models as mainstream heavy draft tractors. Emily Padfield took the 480hp 4500 for a spin.

There something undeniably sexy about the new Xerion. In truth it’s had a bit of the ugly duckling treatment. Whereas smaller 3300 and 3800 models seem ungainly and gawky to look at, the new 4500 and 5000 machines ooze style and yet give a good hint of the brawn that lies beneath the sleek exterior.

It’s a job to know where in the tractor hierarchy Claas’ Xerion actually fits. It’s not a conventional wheeled tractor, yet it has a rigid chassis; it lacks tracks and it’s got four equally-sized wheels. It’s got hp by the bucketload, technology enough to rival its articulated counterparts and can be used year round on the farm for any number of tasks (although sticking a tractor of this size on a dump trailer might be deemed overkill).

Current 330hp and 380hop Xerions are perceived to be specialist “tool-carriers”, the territory of slurry rigs and triple mowers. But Claas hopes the introduction of the two new models will do something to broaden the Xerion’s appeal as a mainstream arable workhorse.

The concept of the 4500 and 5000 range-toppers is the same as smaller models, but everything has been seriously beefed up. Building on the technology of the 3300 and 3800 models, the new machines represent quite a hike in power – offering 483hp and 524hp. This translates to 2203Nm and 2353Nm of torque, all delivered at 1400rpm.

It will be available in two models, the conventional Trac variant and the Trac VC with a rotating cab for reverse-drive operations. Although we drove the 4500, Claas reckons that the 5000 will be the most popular of the two models as the price difference for the horsepower won’t be that great.

Both get a Cat C-13 12.5-litre power-plant with a beefy cooling pack that gives the new Xerions their characteristically large bonnet. To cool its massive block, there’s a hydraulically-driven cooling fan that operates completely independently of engine speed and can be reversed at the touch of a button.

Hitched up to a 5.5m wide Sumo Trio sub-soiler/cultivator, the big machine makes it plain that power isn’t going to be an issue – it’s got shed-loads of oomph. But where it struggles is with traction in tough spots, even with a 2.5t weight on the nose. It really needs full ballasting to put all 483hp on the ground. Surprising when you learn that when it leaves the factory, the Xerion weighs in the region of 16t – about the same as the larger artics in this power range. Front and rear wheel weights provide the opportunity to bring both models up to 24t.

The test tractor’s tyres were 710/85 R38s, measuring 2.15m in diameter. This is said to create an especially long footprint to maximise traction without jeopardising transport widths. Those wanting to run a Xerion on duals will struggle, as Claas insists that, shod on the right rubber, the tractor should be more than capable of transferring power to the ground.

The massive bonnet flips up far more easily than that of smaller tractors, but leaves side panels in place. There’s a three-piece split radiator which looks after engine, charge-air and oil cooling in one, but the radiators don’t slide out.

Fuel tank capacity has been upped from 600 litres to a hefty 1000 litres – enough for 12-hour stints.

While the 5000 is the first tractor over 500hp to get a stepless, continuously variable transmission, the 4500 model we tested is also a newcomer to CVT world. The 50kph ZF Eccom 4.5 is one of the most sophisticated transmissions on the market, according to Claas. We’re not sure that there is much else on the market to rival it so the German giant was probably limited in its choice.

To get going, it’s all pretty standard CVT stuff. Dial in a speed and choose which mode you want to work in, then put your foot on the throttle and go. There’s no joystick control setting, however, there is the usual auto and optional manual modes should the driver want to take control of engine revs for themselves.

What makes the gearbox different is that speeds of 0.05kph to 50kph can be achieved in both forward and reverse, a first for this size tractor.

Up in the four-post cab there have been some major changes. The whole console layout is brand new and there’s a tactile computer-style mouse control that offers finger- and thumb-controls for pretty much everything.

Left and right movements dictate direction, which can be also controlled via a toggle switch on top. It lacks a neutral setting though, so you have to pay particularly close attention when coming to a halt.

The same as that used in Claas Jaguar forage harvesters, the Cebis computer control allows operators to access functions in three ways, either manually working through the menus or via the programmable rotary dial which allows quick access to chosen screens. “Hot Keys” allow further quick access to a number of preset settings primarily for transmission, engine and linkage. Having all these options gets a bit tricky to remember, but there’s a handy escape button to get home should it all prove too much.

For side slopes, there’s an intuitive joystick-controllable feature that allows drivers to crab the rear wheels. Although disconcerting at first, it doesn’t take long to get used to. There are auto and four-wheel steering settings, too.

As you would expect, both 4500 and 5000 models come fully GPS and autosteer ready, all controlled via the Cebis terminal. Both can be configured to work with Claas’ performance-monitoring and fault-diagnosis telematics system, transferring data back to the farm office or dealer workshop.

Sticking 500hp under the bonnet, Claas has sacrificed forwards visibility. Views down to the front weight are pretty much non-existent – a potential problem for road-work.

Operators can choose from up to six spool valves at the rear and two at the front. The pump puts out an impressive 205-litres/min with a separate circuit for steering and brakes.

The Cat III front linkage can cope with 8.4t and is just right for carrying a front press or extra hopper for a seed drill, with handy lift and lower buttons to help operators control things from the front.

The rear linkage can lift a massive 13.6t and there’s a choice of a clevis, piton fixing or ball-coupling. Up behind the cab, there’s another ball-hitch for swan-neck tankers or trailers.

On the road, the new Xerion settles in rather well, with revs dropping to a sedate 1500rpm at 50kph. It’s quite a bit different to driving the smaller models, partly due to the driving position. Instead of being perched on top of the machine, it feels far more like a conventional tractor.

Going down the road, given the big tractor’s size, you get the feeling most other road users would dive into the nearest gateway when meeting you.