The worlds biggest tractor – Challenger MT975


First Drive: Challenger MT975B

The MT975B is the largest in Challenger’s MT900B range and has been primarily designed for the North American and eastern European markets and has not been homologated for Western Europe. With peak power output in excess of 600hp and a maximum operating weight of just over 27t, it’s the world’s biggest and most powerful production tractor.

Everything about this machine is monstrous – its fuel tank takes a good 20 minutes to fill and matches most farm sprayers at 1500 litres – some indication of the 18.1-litre engine’s thirst.

The size of a small suburban semi and with a pricetag to match, it’s got the widest and heaviest frame in the industry (1321mm wide, 3950mm wheelbase), the largest articulation pin and the biggest bar axle (145mm) on offer anywhere. It’s a six-step climb up to the cab.

Challenger MT975B Images

Challenger MT975B: Power, Weight and Size

Challenger MT975B


  • Straightforward controls

  • Good Visibility

  • Tight turning Circle

  • Plenty of power


  • Too wide for UK roads

  • Hefty price tag

  • Operating weight could be an issue on wet soils

The firm claims that making the chassis chunkier provides better weight and power distribution over uneven terrain. The drawbar extends to the centre of the tractor, which is also said to help spread the load to all four corners.

And yet, despite its size, the enormous machine is nimble. Its articulation pivot-point allows 42 degree turns (15.2m diameter turning circle on dual 800 tyres) and 13 degrees of oscillation to keep all the wheels in contact with the ground.

The whole MT900B range uses Caterpillar’s 24 valve ACERT Tier III engines, delivering power through Cat’s 16×4 full powershift transmission – an adapted version of the gearbox used in the construction giant’s dump trucks.

But for those in Western Europe, the MT975B’s size is ultimately its undoing. To get all that power down effectively on a wheeled machine, it has to run on dual wheels, making it far too wide (5.1m) for our roads.

The logical solution – aside from selling it on single wheels and an “optional” set of duals – is to put it on four tracks. It’s a move which has proved successful for other machines, such as Case’s Quadtrac and John Deere’s H-track equipped 9020 series tractors. Challenger however, has no plans for such an adaptation.

Challenger MT975B Video

Challenger MT975B: Test Drive

Most of the controls are on a stubby joystick close to your right hand. Flick the parking brake off, knock the lever into drive, bump up the throttle and away you go.

Steering is light for a machine of such size, although the tight turning circle means you’ll need to watch the drawbar doesn’t get too close to the rear wheels for some kit.

With some 600 ponies under the bonnet itching to be let loose, the machine barely notices anything’s hitched up.

Notching up through the gears is made easy with the fingertip buttons on the control stick – one for up, one for down.

Challenger says that operator comfort has been made a priority within the cab and first impressions suggest they’ve done a reasonable job. Shared with the brand’s twin-tracked crawlers, the cab feels light and roomy, with good visibility all round, although there is a distinct lack of handy cubbyholes.

VERDICT: Challenger MT975B

Challenger MT975B Profile

Rated Power 570Hp
Engine Caterpillar ACERT Tier III, 24 valves, electric fuel injection
Transmission Caterpillar 16 x 4 full powershift
Top Speed 40Kph
Optional Linkage lift 10t
Max operating weight 27.2t
Turning radius 15.2m diameter
Service interval: Engine 250hrs
Service interval: Back end 1000hrs
Price £220,000

The MT975B is undoubtedly a seriously powerful machine, with the size and weight to match. But that’s just its problem. For UK farmers at least, it’s too big and unless a version is launched on tracks instead of wheels, it looks certain to remain the preserve of large-scale growers in eastern Europe and the USA.

There are other tractors out there that can already meet the UK’s needs – both from Challenger and other manufacturers – so maybe this isn’t such an issue. Also, notwithstanding the £220,000 price tag, to get the best out of a machine such as this requires equally large-scale kit and fields – a luxury precious few UK growers have.

Rivals: Challenger MT975B

Case Quadtrac Case Stieger John Deere 9620 Buhler Versatile HHT
Case Quadtrac Case Stieger
597hp 428hp 500hp 580hp
£216,148 £139,440 £155,000 £126,000