Volkswagen Touareg Hybrid 2009 Review - International

What we liked
>> Awesome power
>> Relatively refined drivetrain
>> First hybrid car with a 3.5-tonne towing capacity

Not so much
>> Brakes were too heavy, too sensitive (fixed on subsequent test cars)
>> Gearshift engagement not as smooth as CVT (fixed on subsequent test cars)
>> Battery takes the place of the full-size spare. Instead you get an inflator kit.

Volkswagen has given selected motoring outlets a sneak preview of its first ever hybrid drive system. The technology was fitted to a pair of current model Touareg 4WDs but will appear in the all-new model due on sale about a year from now.

Before Australian customers get too excited, it is worth noting that the vehicle is first being developed in left-hand-drive for the massive North American and European markets. Australian sales won’t be possible until the right-hand-drive version is complete some time in 2011.

The vehicles tested were not fitted with the final system calibrations, but a half-hour drive around VW headquarters in Wolfsburg gave a strong insight into Volkswagen's interpretation of the technology.

Under the bonnet is a 3.0-litre direct-injection petrol V6 (245kW/440Nm) mated to a 38kW electric motor. As with the Lexus RX450h hybrid, the car can be driven on its electric motor alone, in this case up to about 60km/h (the Lexus RX450h petrol engine activates at about 50km/h).

When the power of the petrol and electric motors are combined the vehicle has a total output of 275kW and 550Nm. It can be driven up to 1.5km on battery power alone if the road is flat and light throttle is applied.

Interestingly, VW has opted for a conventional eight-speed automatic transmission as opposed to the continuously variable unit typically favoured by most other hybrids because of their smoothness. The transmission is combined with a special clutch that engages and disengages petrol drive as required.

On the car tested there were subtle jolts as the gears were automatically engaged when the petrol engine fired into action. However, this has been ironed out on subsequent test cars, according to Dr Bernd Stiebels, the head of Volkswagen’s powertrain development and responsible for the Touareg Hybrid.

The brakes were overly sensitive, too. They felt heavy and had too much bite. Both of these concerns have also been fixed on subsequent calibrations, Stiebels said.

Despite these quirks, the Touareg Hybrid test car was an impressive piece of machinery. It accelerated with the power of a V8 but sipped fuel like a diesel.

A digital diagram on the touch screen navigation display shows the driver exactly what the system is doing, and how much fuel you’re using. It also shows you how much battery charge remains, and when the battery is being charged – or drained.

You can exploit the system's full power as long as there is at least 50 per cent battery power in reserve. When the battery pack drops to 30 per cent charge, the petrol engine kicks in until the battery capacity is restored. Regenerative braking means the vehicle recharges its battery pack while on the move such as coasting, braking or driving downhill.

Volkswagen says it has gone to great lengths to ensure there are no compromises with the Touareg Hybrid and claims the new vehicle has a class-leading (and hybrid world first) towing capacity of 3.5-tonnes.

The nickel-metal hydride battery pack is mounted in the spare wheel well under the cargo floor. The downside is that you may not want to venture too far off the beaten track without a spare. Instead the Touareg Hybrid comes with a tyre inflator kit. This system works well in principle but is no help if the sidewall has been split. Volkswagen offers a rear-mounted spare-wheel carrier as an option on the current Touareg -- perhaps that could be standard on the hybrid in the next generation.

The entire hybrid system including the battery pack and electric motor and ancillaries adds 175kg to the weight of an equivalent Touareg V6, and the test cars weighed about 2.5 tonnes. However, the new generation Touareg is likely to weigh much less than the current model and is understood to have gone on a weight loss program that has shed at least 200kg.

Volkswagen has been working on the Touareg Hybrid since 2005. It has taken four years to learn about the technology and test it in the harshest conditions. The company says it has put the car through its paces in temperatures ranging from minus 35 degrees Celcius to 45 degrees Celcius plus.

Hot weather testing revealed that the team needed to find a better way to cool the battery, thus there is an air duct under the car that directs air from the area just above the rear axle and onto the battery pack. There is also a vent under the rear passenger seat to keep the battery pack cool. [Ed: should be great for river crossings!]

Volkswagen says the Touareg Hybrid is 17 per cent more fuel efficient than a non-hybrid petrol V6.

Despite a number of European brands announcing diesel hybrid cars, Volkswagen says it has no plans for a diesel hybrid at this stage.

"For sure the diesel would be more efficient again, but the torque characteristics of the engine don’t work as well as they do in a petrol engine. Plus a diesel engine is more expensive than a petrol engine, and so the improvement is not so great when you consider the extra money spent," Stiebels said.

Ironically, although Volkswagen led the development of the hybrid system for the Touareg, its affiliate Porsche is likely to debut the technology first -- on the Cayenne 4WD by the end of 2010.

Price Guide: Volkswagen has indicated it will be at a premium above the regular V6. We’re speculating about $85,000 – $10,000 more than the V6.
Engines: 3.0-litre direct injection petrol V6 with a 38kW electric motor.
Power: 275kW and 550Nm (combined), the V6 on its own has 245kW and 440Nm.
Consumption: Less than 9.0L/100km.
Emissions: not disclosed.
Transmission: Eight-speed automatic with special clutch to engage and disengage the electric motor.
0 to 100km/h: Less than 6.8 seconds.
On sale: As a left-hand drive from late next year. Not yet confirmed for right-hand-drive production.

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