We like
Torque, economy, car-like road manners

Room for improvement
No automatic version, minimal rearmost luggage space

TOYOTA has joined the rush to big-banger four-cylinder diesels with its latest, updated version of the Prado 4x4.

Joining Nissan, Isuzu-Holden and Mitsubishi, the company has given its strong-selling medium-weight off-roader a touch of the rugged, workhorse character that fits so nicely into the 4WD wagon genre.

The new engine is a 3.0-litre four-cylinder - nothing unusual these days - and is strong on torque, with a solid 343Nm wound out at just 2000rpm. This means it has the most torque in the Prado range, significantly stronger than even the 3.4-litre V6.

It's not quite as strong in a competitive sense as Toyota would have you believe, though: The smaller capacity five-cylinder turbo-diesel in the Mercedes-Benz ML270, for example, thumps out a staggering 400Nm - at just 1800rpm - while the new Nissan Patrol 3.0-litre four-cylinder turbo-diesel produces 354Nm at the same 2000rpm as the Toyota.

The Prado turbo-diesel is of basically simple design, contrasting to the common-rail, direct injection, multi-valve twin-camshaft technology employed by some other manufacturers. The engine uses an iron block, alloy head, single overhead camshaft design with two valves per cylinder, twin balance shafts to reduce vibration and electronic fuel injection using a fly-by-wire throttle.

The water-cooled turbocharger operates through an air-to-air intercooler for combustion efficiency and the injectors pulse fuel into pre-combustion chambers. Torque output is assisted by the relatively pronounced long-stroke design that sees a bore/stroke configuration of 96mm/103mm.

Toyota says the new engine is low in emissions, with carbon monoxide levels at one 20th of the level specified by Australian Design Rules, and hydrocarbon emissions at one fifth of legal requirements. Toyota doesn't talk too much about the typical diesel smoke output, but does say it easily passes legislated requirements.

And naturally the turbo-diesel picks up the usual fuel economy advantages. It is the most economical of all Prados and with a capacity of no less than 159 litres there are many places to go on just one tank of fuel.

Changes to cope with the extra torque of the new engine include a new, heavier-duty clutch and a bigger radiator.

On the road, all this translates to a nicely responsive diesel Prado, not particularly loud and relatively smooth with the twin balance shafts. It operates more quietly than the Holden Jackaroo turbo-diesel, but is not quite as hushed as the similarly engined Nissan Patrol.

Some of the noise control is no doubt due to an interesting double-skinned bonnet that channels air from the grille area to the intake system, doing away with the often-used trademark bonnet scoop signifying that something turbocharged lies within.

The engine, as expected, responds quickly to the accelerator, only showing signs of turbo lag if the driver attempts planting the boot under 2000rpm.

Generally the oil-fired Prado feels muscular and capable, certainly a good prospect for towing with its impressive low-speed and mid-range torque.

Only available as a manual initially, the turbo-diesel now also comes with a four-speed automatic. The manual is a smooth-enough shifter, but the auto will add signficantly to the turbo diesel's general appeal. Toyota now joins Holden, which offers an automatic with its turbo-diesel Jackaroo, and Nissan, with its turbo-diesel Patrol.

The Prado is otherwise the same impressive medium-weight 4x4 that has helped secure Toyota's place in the urban off-road wagon market.

Lighter and wieldier than a LandCruiser, but still a capable all-rounder with a dual-range, full-time 4WD system, the Prado has proven to be the right formula for many Australian users.

Its road manners tend more towards those of a car than some of the larger wagons, yet it still offers a full eight-passenger carrying ability.

Suspension is by double wishbones at the front while the rear features a live axle, multi-link set-up that provides passive rear steer for better turn-in and grip during high-speed cruising.

It might tend to look slightly high and narrow, but from the cockpit it feels secure and essentially is, helped along by no small means by the security of the full-time 4WD.

Added to this is a steering system that is well weighted and responds accurately to driver commands, secure all-disc anti-lock brakes and a smooth, absorbent ride provided by a suspension comprising independent double wishbones at the front and coil springs at the rear.

Dual front airbags and anti-lock brakes are standard on TX, VX and Grande models, optional on RV and GXL, while the V6-engined VX and Grande models also get traction control as standard.

The TX version tested gets a touch of wood grain on the dash, a chrome grille with horizontal slats and a spare wheel cover to identify it from the GXL and RV models.

All models come with three rows of seats providing an eight-seater capacity, while air-conditioning is standard in TX, VX and Grande - manual in the TX, automatic in the more upmarket versions.

The Prado has been somewhat more successful for the company than its predecessor, the more utilitarian Four-Runner, and the addition of an efficient turbo-diesel only strengthens the case.