Off on a big Adventra

By ALASTAIR SLOANE

The Holden Adventra, the first all-wheel-drive crossover vehicle designed, engineered and built in Australia, will go on sale in New Zealand in January.

There will be two V8-powered variants, the base model CX8 and the top-range LX8. No word on price yet, but Holden Australia launched both last week and listed the CX8 at A$52,990 ($60,650) and the LX8 at A$60,990 ($69,800).

Word on the street has it that New Zealand buyers can expect the CX8 to be up to $10,000 more expensive than the $59,000 V8 Berlina wagon.

The Adventra is the result of a $130 million investment by Holden and is essentially its answer to the Subaru Outback and Volvo XC70.

Holden managing director Peter Hanenberger said the new model was the "cornerstone of the company's future".

"Adventra is the first in a range of advanced all-wheel-drive vehicles from Holden that will change the way [we] drive.

"With the Adventra, Holden is now placed to enter and take advantage of a new automotive era that will develop over the next decade, that of the all-road crossover.

"As the car market fragments and diversifies worldwide, the only manufacturers which will prosper are those which deliver a wide portfolio of niche products designed for that fragmenting market.

"Adventra is a prime example of our ability to develop models quickly and efficiently, which will ultimately guarantee our long-term viability on the world stage."

The Adventra is based on the Commodore station wagon but has 350 unique components, including an optional third-row seat, dedicated wheels, underbody protection plates and a new twin-piece tailgate that allows the glass to be raised independently.

Its body is 11mm longer and 87mm wider than the Berlina. It rides higher, too, by 80mm. The wheelbase is longer, by 10mm, and the footprint is wider, by 58mm at the front and 46mm at the rear.

It also weighs about 200kg more than similarly equipped V8 Berlina wagons.

The extra weight is taken up by the all-wheel-drive system and the greater bulk of the vehicle. Stronger chassis, bumpers and wheel arches for off-road work and more durable mechanical components like heavy-duty brakes add to the weight, too.

So does a special oil pan that allows the Adventra to be driven at length on angles that would stump a passenger car.

The new model rides on standard 17-inch wheels and revised front and rear suspension designed for a more rough and tumble life.

It is powered by a 5.7-litre V8 engine producing 235kW at 5200rpm and 460Nm of torque at 4000rpm, and mated to a four-speed automatic gearbox modified to accept a transfer case for all-wheel-drive.

Gearbox ratios remain the same as the V8 Berlina, although final drive is slower at 3.46:1 because of the Adventra's bigger off-road wheels.

The transfer case is the same one used in the four-paw version of BMW's 3-Series, which is not sold in New Zealand.

It is teamed with Holden's newly developed Cross Trac system, which has three open differentials front, centre and rear to direct drive 62 per cent to the rear wheels and 38 per cent to the front.

Holden deliberately dialled in the rear-wheel bias to maintain the Commodore feel. There is no low range.

Cross Trac uses software developed for General Motors Hummer H2 programme, the civilian version of the American military off-roader Humvee, but Holden modified it. Unlike many all-wheel-drive systems based on traction control electronics, Cross Trac does not reduce engine power when one or more wheels start to slip.

This helps traction in sand and gravel and is part of why Holden tuned the system to suit varying road surfaces in Australia and New Zealand. It tested the Adventra on more than 600,000km of South Island roads in the winter and various desert tracks in Australia in the summer.

Said Adventra engineering manager Grant Jamieson: "Cross Trac's strength lies in the way it is calibrated to cope with the deformable road surfaces, such as sand, gravel and loose dirt we typically encounter in Australia."

"It uses multiple inputs to the Adventra's computer to determine what the car is doing and what you really want it to do.

"Because our system is wheel-based, rather than relying on modulation of differentials before changes to wheel slippage are made, the conditions the car senses are measured at the source - the wheel. In essence, Cross Trac reacts more directly."

Holden had to recalibrate safety systems such as airbags to suit the heavier Adventra. It crash-tested the robust wagon 15 times to ensure the safety systems worked.

It also borrowed the Range Rover technique of driving the car over railway sleepers to ensure the airbags didn't deploy unnecessarily.

The Adventra will be available only with the V8 engine initially.

A six-cylinder model will appear later next year when Holden begins building its all-alloy V6 at a new engine plant in Melbourne.