John Deere has added two new combines to its W-Series range and replaced its 1450 and 150 combine models.

The five-walker W550 and six-walker W660 (and W660i) models offer the same basic specification as the existing machines, but have more horsepower – 290hp in the case of the W550 and 350hp in the case of the W660.

Engines are 6.8 -and 9-litre John Deere PowerTech Plus six-cylinder turbocharged units respectively, with a fuel tank capacity of 800 litres. Both combines are also available with the optional HillMaster II levelling system.

The i-Series versions are equipped as standard with HarvestSmart automatic feedrate control, AutoTrac assisted steering and Harvest Doc software. Deere claims these versions give a 23% jump in capacity compared with their non-i equivalents.

John Deere’s new ProDrive automatic transmission is also optionally available on the W660 model.

The four-stage threshing system begins with the large 660mm diameter cylinder and longer 750mm concave. A rear beater and second concave provides additional threshing, and pushe the crop to the long 11-step straw walkers.

Further separation is provided by the tined Power Separator, which combs the straw mat to release trapped grain, much like the tines on John Deere’s rotary C and S Series combines.

On the 600R Series headers, the HeaderTrak lateral tilt system can be programmed to automatically maintain preset stubble height and header ground pressure for different crops and conditions.

Meanwhile, Deere’s 1450 And 1550 combines are being replaced by the 1470 and 1570 for the 2010 season.

Spec improvements include a new feeder house to give a smoother flow from the table and a new hydraulic system that delivers faster response times when lifting the table or changing reel speed.

Improvements have also been made to the steering, electrical, shoe drive and straw chopper drive systems.

The 204hp five-walker 1470 and the 262hp six-walker 1570 combines have conventional threshing cylinder and straw walker designs and grain tank capacity is 6800 litres on both models.

Both hydrostatic drive models offer a choice of 600R Series headers from 4.3m to 7.6m. The optional HeaderTrak system provides automatic control of header height and lateral tilt when working on slopes or uneven ground, at night or in laid crops.

In the cab, the dual display InfoTrak monitor allows the driver to display any two functions at once for a clearer picture of the combine’s performance.

The straw chopper can now be switched on and off by simply moving the straw hood from the windrowing to the chopping position. The optional chaff spreader is also now adjustable from the cab, too.