NISSAN has called its stump-pulling V6 diesel to the frontline in a bid to return fire in the one-tonne workhorse ute war.

Challenged by Ford’s all-new Ranger, Mazda’s equally fresh BT-50 and the revised Toyota HiLux, Nissan’s seven-year-old Navara D40 dual-cab range has been re-enforced with new equipment, revised pricing and a new, more affordable model powered by its top-shelf V6 diesel.

It has also fitted electronic stability control (ESC) as standard on all dual-cab 4x4 models, not just the flagship ST-X and ST-X 550 variants.

Previously, the fearsome Renault-sourced oil-burning V6 - which produces some 170kW of power and 550Nm of torque, making it the most powerful engine in its class - was only available in the ST-X 550, which cost $60,990 plus on-road costs.

Now it is available with the ST-X, priced at $56,990 plus ORCs, which $3750 more than before but because a manual transmission is not fitted with the brawny V6 diesel engine it now comes standard with a seven-speed automatic with manual mode as standard.

Apart from a potent diesel V6 – which is a considerable jump up from the 2.5-litre four-cylinder diesel that used to reside beneath its bonnet, the ST-X now also comes with foglights, dark tinted windows and rear under-seat storage.

Meantime, the upgraded ST-X 550 flagship now costs $2000 more than before with a hefty asking price of $62,990, but now comes with all the gear that was part of an option pack previously valued at $4000.

This includes leather seat trim, heated front seats, satellite-navigation with three-dimensional mapping, a seven-inch display screen, reversing camera and a Bose sound system with 9.3GB of music storage.

A hard tonneau cover, which was previously fitted, has been removed but will remain an option.

The most popular model in the Navara range, the mid-spec ST, still runs a 2.5-litre four-cylinder turbo-diesel but this one gets a more powerful tune with 14kW and 47Nm of extra performance for a total of 126kW and 450Nm. This is the same engine specification as the previous ST-X.

Its fuel economy improves by 13 per cent to 8.5L/100km for the manual and 9.0L/100km for the automatic.

A six-speed manual is still standard, while the optional five-speed automatic now has a manual mode.

The ST now also gets six airbags, 17-inch alloy wheels, body-coloured wing mirrors and a flexible tray load mounting system Nissan calls Utili Track.

Now sourced from Spain instead of Thailand (where the RX is still made), the ST now has a slightly different grille, headlights and front bumper, coming into line with the other models sourced from Spain.

Interior changes include a new-look centre cluster and console, revised switchgear, upgraded seat fabric and dual-zone climate-control. Also new is a six-speaker sound system with USB port and Bluetooth phone connectivity.

Nissan has raised the price of the ST by $3000 to $46,800 for the manual, while a five-speed automatic version now costs $49,050.

It argues the extra equipment more than makes up for the price increase and says it stacks up well against competitors both old and new.

The RX, which kicks off the Navara 4x4 crew-cab range, essentially stays the same except that it now comes standard with ESC and has three-point seatbelts on all seats.

Nissan did not add to the front driver and passenger airbag allocation, deciding against fitting side and curtain airbags that are installed in the other 4x4 crew-cab Navaras.

Even so, all 4x4 crew-cab Navaras including the ST now qualify for a four-star ANCAP crash test rating, which is an improvement but still short of the maximum five-star result achieved by the Ranger and Amarok.

Nissan has kept prices of the ST, which retains a 106kW and 356Nm 2.5-litre four-cylinder turbo-diesel, locked in at $39,600 for the cab-chassis dual-cab and $41,300 for the dual-cab with a regular steel rear tub.