The John Deere 8R Series has a new flagship model in the form of the 400hp 8400R – the most powerful standard tractor to ever be made at the company’s Waterloo factory.

Powered by a new John Deere 9-litre Stage IV engine, the 8400R boosts up to 450hp and is fitted with the 100% mechanical e23 transmission.

According to independent drawbar tests, the existing 8370R already out-pulls its nearest competitor, putting 340hp out at the drawbar compared to the next highest at 325hp.

With this new 400hp model, drawbar power jumps to 360hp, offering 91% power efficiency.

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Deere hasn’t just tweaked the engine to produce this extra power, it says. It has also upgraded the piston design to deliver a better air-to-fuel mixture.

This, in turn, has improved fuel consumption by 2% over the 8370R and Deere says that these engine changes will probably filter down to the rest of the range next year.

Although the front cooling package hasn’t changed dramatically, cooling round the base of the engine has been updated, too.

With this model aimed predominantly at field work, it comes as no surprise that the only transmission offered is the e23, which is 100% mechanical and delivers what the Green Giant says is the best power to rear-axle efficiency, at 94%.

Not only is it more efficient, says Deere, but it’s also extremely durable for high hour use.

The rear axle has also been upgraded and now features a double flat design with an overall width of 255cm. This configuration, which is borrowed from the 8RT series, gives 212mm rather than 152mm damping surface.

For those who want to add extra weight, new ductile iron hubs allow for 970kg rear wheel weights to be added.

From mid-2017 the 8400R Series will come with the Generation 4 touchscreen CommandCentre display which allows customers to run multiple screens and move windows around to suit the application.

Like other 7R, 8R and 9R Series tractors, connectivity for precision farming comes in the form of FarmSight, with a newly launched StarFire 6000 satellite receiver as well as five-year JDLink and upgraded signal offerings.

Production is due to start in November and dealers are able to take orders now for the new model. uide price is around £230,000 with e23 40kph transmission, 900mm wide tyres, independent link suspension, standard lighting, Cat 4 drawbar, 9,000kg rear hitch, four spools and JDLink. The 8RT Series will be refreshed next year.

5R returns

John Deere’s new 5R series bridges the gap between 5M and 6M/R models and is designed to be compact but versatile.

Although Deere had a 5R until a few years ago, options have lacking over recent years and customers have been keen for a model to fill the gap.

The relatively high-spec four-model range is powered by a four-cylinder, 4.5-litre engine which has a transport only boost of 10hp.

The range comprises the 90hp 5090R, 100hp 5100R, 115hp 5115R and the all-new top dog, the 125hp 5125R.

Each model has a wheelbase of 2.25m and features a natty curved frame design to deliver a turning radius of 3.75m, even when fitted with a front loader.

Because the engine is mounted deep in the chassis, the 5R has an pretty low centre of gravity that makes it well-suited to loader work, says Deere.

Although the 5R Series has a 4.3t shipping weight, these perky four-pots can still lift 4.7t and the 5125R offers a best-in-class power-to-weight ratio of 34kg/hp.

The tractors are available with a choice of three transmissions, to include the entry level 16/16 CommandQuad Manual, the 16/16 CommandQuad Auto and the 32/16 Command8.

A new cab, with optional maintenance-free cab suspension, gets all the features of the higher-horsepower R ranges, with corner post display, panoramic front windscreen and a range of joysticks. 

Fitted as standard with a 96-litre/min hydraulic pump, it is possible to spec a 117 litres/min pressure and flow regulated option, too.

John Deere has also launched a new 543R front loader, which has 10% higher lift capacity, increased breakout force and more roll-back angle, as well as a neat lighting option for hitching on implements in the dark. 

Guide price for the 5125R starts at around £61,271, while the loader starts at £5,858.