DIESEL continues to be the fuel of choice among four-wheel-drive wagon buyers, despite a 30 per cent price penalty at the pump.

Mitsubishi this week unveils a more powerful version of the turbo diesel engine in the Pajero, an engine that already accounts for 70 per cent of Pajeros sold.

The new model, the NT, takes over the mantle of most powerful in its class from the Toyota Prado.

It is also quicker, quieter and more frugal than the NS it replaces, has a higher towing capacity and is available in a wider model range.

Returning after a two-year break is the base model GL, aimed at fleets and budget-conscious private buyers.

Also returning is the GLS, slotting in between the GLX and VRX.

Power and torque output in the 3.2-litre four-cylinder diesel jump 18 per cent to 147Nm at 3800rpm and 441Nm at 2000rpm.

This is 16 per cent more power and 8 per cent more torque than the Prado diesel, updated late last year.

A new Aisin five-speed automatic transmission replaces the previous Jatco gearbox and has its service intervals extended to 90,000km.

Most gear ratios are taller along with a taller final drive to make the most of the higher torque and reduce engine revs when cruising to 2000rpm at 100km/h.

As a result, fuel economy has improved by up to 13 per cent to a combined 9.2 litres/100km in the diesel automatic and 8.4 litres/100km in the manual (GX, GLX and GLS).

Towing capacity has jumped 500kg to 3000kg (2500kg on the short-wheelbase models).

That's 500kg more than the Prado and comes with a maximum towball download of 180kg.

Exterior changes are cosmetic - revised grille and alloy wheels and some additional side garnish.

Engine changes include a revised injection and swirl system to improve combustion, revised intake ports, a larger turbocharger and improved emission controls.

These, together with more sound insulation, have brought a welcome reduction in engine noise.

The 3.6-litre V6 petrol engine continues unchanged as does the full-time, dual-range, four-wheel-drive system. The GL is the diesel-only entry level five-seater but still has stability control, traction control, anti-skid brakes and optional side and curtain airbags, third-row seats and a rear diff lock.

All other models GLX, GLS, VRX and Exceed have seven seats. The GLX is unchanged but the GLS includes side and curtain airbags, rear air-conditioning and side steps.

The VRX moves upmarket adding full leather trim, power front seats and a rear diff lock on diesels.

The Exceed gains new 18-inch alloy wheels, rain-sensing wipers, dusk-sensing headlights and a more integrated audio and rear entertainment system.

Sales of traditional off-road medium-sized four-wheel-drive wagons (Prado, Pajero and Pathfinder) has remained static in recent years and is likely to remain so.

At the same time the volume of so-called soft-roaders has doubled.

Pajero prices are up by about $1300 but Mitsubishi says they are offset by more equipment and will still undercut the Prado.

They range from $47,490 for a manual diesel GL (auto $50,790) to $74,790 for an auto diesel Exceed. Short wheelbase models range from $43,900 for an auto V6 R to $53,490 for an auto diesel X.