First drive: VW Touareg Hybrid ready to roll
BY JAMES STANFORD | 18th Sep 2009
Final fuel consumption testing results are yet to be revealed, but engineers had been given the task of achieving 8.5 litres per 100km – an impressive number for such a large car.
This represents a fuel economy gain of more than 25 per cent, but the Touareg Hybrid also promises improved acceleration and the ability to tow loads of up to 3500kg.
However, VW Australia is yet to decide if the high-end – and possibly pricey – vehicle will make it to Australia any time soon.
GoAuto spent time with Touareg hybrid development engineers in Volkswagen’s Wolfsburg headquarters today and was briefed on the vehicle before a test drive in early prototype vehicles.
The team could not give away all the details, because information about the upcoming new Touareg range is yet to be released, but they painted a detailed picture of how the important SUV would function.
An ‘E-motor’ electric motor sits between the engine and the gearbox, delivering 30kW and 110Nm of assistance.
The hybrid components add 175kg to the Touareg’s weight. However, the new Touareg’s body will be significantly lighter than the current version, meaning that the Touareg Hybrid is expected to weigh about 2250kg when it enters production.
Despite its heft, the Touareg Hybrid prototype is still capable of surging from 0-100km/h in just 6.8 seconds. Insiders suggest the production vehicle will be another 0.3 seconds faster.
While Toyota and Lexus hybrids use a continuously variable automatic transmission (CVT), the Touareg Hybrid uses a regular Aisen torque converter automatic transmission with eight gears.
It does not receive the lockable centre differential and low-range transfer case of the existing car, but does have constant all-wheel drive.
Volkswagen said the car was still extremely capable off road even without low-range gearing, thanks to its low-end torque.
As long as the driver is easy on the accelerator, the car can run in pure electric mode up to 50km/h before the combustion engine takes over.
The combustion engine stops when the driver backs off the throttle, up to 160km/h.
If the driver reapplies the throttle gently, the car can continue at some speed before the petrol engine starts up again.
The Touareg Hybrid also shuts down the combustion engine at idle. Ancillary systems such as headlights, sound system, heating and air-conditioning can draw energy from the electric motor, although after a while the combustion engine will need to kick in to keep energy levels high.
The hybrid SUV has a 79kg 240-cell nickel metal hydride battery pack below the rear cargo floor. It uses the same technology as the Toyota Prius and its competitors.
It generates 288 volts and stores 1.7 kiloWatt hours of electricity.
The battery is housed in an aluminium case that is cooled by an air vent that sucks in air from below the car. Although it sits in the spare wheel well, and the luggage floor still has had to raised 50mm.
At this stage there is no plan for a spare wheel of any kind, just a repair kit, but Volkswagen could end up offering a mounting to make sure owners do not get stuck in the outback.
The vehicle runs low-rolling resistance tyres for maximum efficiency.
The battery gets a top-up charge from regenerative braking, in which the electric motor reverses the current under deceleration while helping to slow the car.
The Touareg Hybrid initially accelerates in electric-only mode before switching to combustion engine-only mode, but if the driver floors the accelerator or pre-selects a special S mode, both powerplants go to work at the same time.
Healthy performance and the ability of the Touareg Hybrid to tow heavy loads was central to the vehicle’s development.
“We wanted this to replicate the Touareg driving experience,” said Touareg Hybrid project manager Dr Bernd Stiebels. “Customers like the Touareg. We couldn’t allow any compromises.” Dr Stiebels said Volkswagen did not want the Touareg Hybrid to be like the Lexus RX450h, which is not designed to go off road and had a reduced towing load.
“It (the Lexus) looks like an SUV, but it isn’t an SUV,” he said.
This is one of the reasons why VW refused to use a CVT and instead developed the regular automatic.
It said a CVT would not have been able to cope with the necessary extreme towing loads and uphill driving.
When the vehicle goes into electric mode, it free-wheels, without engine braking.
This could be a problem for extreme off-road work when drivers rely on engine braking to slow their descent.
Volkswagen would not discuss the details but said it had a solution for this problem.
Elements of the Touareg Hybrid system including the E-Motor unit – developed with Bosch – will be used for other Volkswagen Group vehicles.
It will be suitable for small-car platforms and can be adapted to double-clutch DSG automatics.
Volkswagen said it was already looking at next-generation lithium ion batteries, but said it was not yet convinced they were ready for cars.
The company is yet to reveal a price for the hybrid model, but Dr Stiebels said it would be “one of the top-end models in the Touareg range”.
The Touareg Hybrid model will look largely the same as the regular combustion-engined models, although there will be some small design touches to help the car stand out.
It is not yet clear when the Touareg Hybrid will touch down in Australia.
Volkswagen Australia said the car was not on its short-term model plan and would have to be carefully considered given its premium price and relatively low numbers.
Drive impressions:
PROVIDED the price is right, the Volkswagen Touareg Hybrid is likely to be a compelling vehicle because it is so good to drive.It might be relatively green, but that does not mean puny performance. Like most other SUVs, it can tow serious loads and climb serious hills, and still provide healthy acceleration.
At least, that’s the impression GoAuto gained in a drive of a prototype – the new petrol-electric hybrid powertrain stuffed into a current body. Our final opinion will have to wait for the production model, which will have the benefit of an all new and significantly lighter body.
We were warned of teething problems in the prototype, including the odd ordinary gear change, but it was generally excellent, if a somewhat strange experience.
The hybrid drivetrain makes no noise when creeping away from standstill on electric motor power.
Apply some throttle and the combustion engine quickly comes in. Take it easy and 50km/h or so might be achieved before it fires up.
Unlike the rough ebngine start-up of many current idle-stop cars, the Toaureg Hybrid’s petrol changeover is hardly noticeable, so much so that from the rear seat, you have to keep an eye on the tacho to see if the engine is on or off.
At cruising speed, lifting the foot from the throttle pedal stops the engine, and everything goes quiet. Gently touching the accelerator pedal will keep the car going nicely on electric power.
Some customers might expect a hybrid SUV to run for far longer on the full electric mode, but when you are driving a car this big and heavy, that simply is not possible.
The prototype achieved an impressive consumption figure of around 7.0L/100km on one section – remarkable for a vehicle of this size. That said, lead-footed drivers have no guarantee of saving much fuel.
They will, however, have some fun. The acceleration of the Touareg Hybrid is so strong that when the electric motor and petrol engine combine that the temptation to put the foot to the floor is almost irresistable.
Aa a few lucky Audi S4 owner already know, the supercharged 3.0-litre engine powering the Touareg Hybrid is a good engine, serving lashing of smooth low-down torque.
Add electric motivation as well and the hybrid prototype apparently can run a 0-100km/h sprint just as quickly as a high-performance R50 diesel Touareg, even leading for much of the distance.
Unlike most hybrids that use quirkly CVT transmissions, the Touareg Hybrid uses a conventional automatic with conventional shifting qualities and none of that CVT slipping sensation.
You can’t, however, forget it is a bulky vehicle in the corners, but it is, afterall, an SUV Despite a cargo floor that sits 50mm higher than normal to cater for the battery bulging from the spare-wheel hole, there is still heaps of luggage room.
At this stage, the solution to a flat tyre is a repair kit consisting of a can of goop which is unlikely to be of much use when there is a gaping hole in your sidewall.
Volkswagen Australia said it hoped some form of external wheel holder would be made available if the Touareg Hybrid came here.
It is unclear how much the lack of a transfer case and crawler gears will be an issue off road. The engineers working on the car say the electric hybrid drive will be a benefit, helping in tight spots.
However, Volkswagen makes some cracking diesels, especially in the V6 form, and they as simpler than the hybrid and lighter too.
But if a hybrid appeals, the Touareg Hybrid will be tempting unless it is priced out of the class.
We will have to wait and see the production version, but the prototype shows the customers do not have to compromise to drive a relatively green car.
