There’s something uncompromisingly gargantuan about the Case IH Quadtrac. Its sheer presence is enough to make you stand and stare, and you can but marvel at the way the 76cm (30in) tracks gobble up the acres barely leaving a mark.

The new Quadtrac range involves four models that go from 502hp to 670hp. In fact the Quadtrac 600 is the most powerful (and, at £353,595, expensive) production tractor on the UK market (alongside its wheeled cousin the NH T9.670) and it’s also the first articulated tractor to offer four-point cab suspension as an option.

The bigger 550 and 600 models are fitted with a two-stage turbocharger instead of the standard wastegate arrangement on the 450 and 500, providing the new power boost feature. There are also two variants of the new models – a narrow-framed model that can only come with wheels (the Steiger) and the wider framed Quadtrac.

Despite having three litres less capacity than the previous 15-litre Cummins that powered the 530 and 535 models (which peaked at 597hp), the six cylinder 12.9-litre FPT Cursor engine puts out a maximum power of 670hp at 1900rpm. Rated at 608hp, the new engine now has the ability to boost power during pto, hydraulic and transport modes when loads demand – just like the Puma and Magnum ranges.

Extra power becomes available when the engine registers enough load on either pto, hydraulic and transport tasks. On the 600, this is a 41hp boost, taking its standard 608hp up to 649hp without any need for engine speed change.

Another change is the arrival of Selective Catalytic Reduction (SCR), CNH’s chosen method of meeting Stage 3b emissions targets. Users will notice a wider section at the bottom of the exhaust stack – this is to house the catalyst which treats exhaust gases with AdBlue urea.

What SCR allows the engine to do, says Case IH, is run at its optimum power. “We’ve gone back to having pre-Tier 3 engine performance characteristics,” explains Case-IH’s Paul Freeman.

And the change shows, with the new engine bristling with power. There’s no delay in pick-up and it doesn’t feel inhibited in the slightest. Early indications suggest an improvement in fuel efficiency of up to 9%, claims the company.

The transmission remains pretty much the same; however the 16F x 2R unit has been beefed-up to cope with the extra power and there’s a strengthened driveline and rear frame. Although a straightforward powershift transmission, the Automatic Productivity Management (APM) feature allows for 2% fuel improvements thanks to its CVT-like trick of allowing the driver to set a forward speed and the engine management to then automatically regulate emgine revs and gear choice to maintain performance.

Adding a four-point cab suspension is a welcome one, with coil springs, pads and mounts joined together by torsion bars and longitudinal rods isolating the cab from chassis-created vibrations. On paper that means no more feedback on the road and a smoother ride in the field to boot.

In practice the ride quality is impressive and driving at an angle over ridged salad beds produced hardly any bumping.

To compare old with new, we drove the host farmer’s existing 530 (no suspension) at the same speed over the same ground. The jolting was certainly enough to make you spill your coffee, drop your lunchbox and possibly loosen the odd tooth.

Despite its 7.61m length, 3.95m height and 24t weight, this 670hp monster is surprisingly easy to swing around and will turn in just 5.7m. You need to avoid sudden movements, though, otherwise whatever piece of kit is behind will be pitched about. The tractor is bang on 3m for transport and taking the folded 6m Simba SLD cultivator we used for the test through a standard gateway seemed no more hassle than a 200hp tractor with a trailer.

A saddle-style fuel tank mounted at the rear now holds 1,883 litres instead of the 1,100 litres in the previous model. Case-IH reckons average fuel use (depending on the job, obviously) will be about 100 litres/hr, so there’s now fuel for a full day’s work.

The first thing that strikes you is the size of the bonnet compared to the older 530. To house the new engine and beefed-up cooling pack, it looks like you could park a small car on the front and still have space for a picnic.

Strangely, up in the cab, this super-sized bonnet doesn’t affect visibility. And the catalyst housing on the exhaust is neatly hidden behind the corner post of the cab so as to not inhibit the driver’s vision.

The cab has been given a radical makeover and now gets the multicontroller armrest common to all Case-IH tractors from the Maxuum up. The multi-function joystick lets you to set forward speed, direction changes and hydraulic and lift controls. All other functions are located on the control panel located directly behind this. The new AFS Pro 700 touchscreen is now mounted on the armrest, and gives you direct access to vehicle settings and performance indicators, as well as two video inputs.

Case-IH says it sells 20-30 of these giants in the UK each year, mainly to large farming companies and those sharing kit with neighbouring businesses. Standard spec is luxurious, with leather seat, steering wheel, carpet and the new AFS Pro 700 screen.

David Jones, of Hatton Bank Farm, Stratford-upon-Avon, Warwickshire, is a bit of an expert when it comes to high-horsepower Case-IH tractors.

As well as running one half of a 2200ha (5440-acre) arable enterprise, Mr Jones is well-known in the tractor-pulling sphere for his Just Smoky rig, a souped-up MX285.

But raw horsepower isn’t all that’s driving the decision to run Quadtracs at Hatton Bank Farm. “We’ve based this system around having a prime-mover like a Quadtrac,” explains Mr Jones. “We adopted min-till more than 13 years ago, and needed a tractor that would be able to transfer enough power to the ground when pulling the cultivation trains we were working across our undulating land.

“Headlands are also extremely important as they make up 25% of the farm, so protecting them is paramount. There’s no scuffing or soil disturbance when turning and compaction is kept to a minimum.”

Having started off with a wheeled 9350 Steiger in 1997, he moved to a 9380 400hp Quadtrac when acreage rose to 2,600 acres in 1999. This model was replaced with the 450STX, the generation before his existing 530. There’s also an STX 535 on the sister farm in Bedfordshire

Mr Jones has been in Quadtrac focus groups for 10 years and starting evaluating the new models 18 months ago in the USA.

“The limitations of the 530 were a lack of ride comfort and juddery gear changes under load. The new suspension limits vibration both on and off-road, and the gearbox is a lot smoother.”

But what does Mr Jones think to the dual-fuel aspect of the new Quadtrac? “I don’t believe it will be difficult to get used to having another fuel on board. It’s made such a difference to performance that the extra hassle of topping it up every other diesel fill-up will be negligible.”

“This engine is sharp and has raw horsepower, it seems to be using the fuel for what it’s supposed to do rather than recycling it for calming emissions, like the previous generation,” he adds. “Engines should also run cleaner, which could make a difference to maintenance bills.”

Mr Jones also believes there are improvements in fuel efficiency to be had from the new models. “I’m hoping to run a 70-80hp larger engine for the same amount of fuel, thanks to the new engine and being able to throttle back during applications.”