Test-Driving VW’s Touareg Hybrid SUV

By dancurranjr On February 15th, 2009

0211_vwOne by one, German carmakers are genuflecting before the hybrid god. The latest is Volkswagen . Like BMW  and Daimler , the company initially resisted the hybrid trend, reasoning that similar gains in fuel consumption and emissions were possible at lower cost simply by optimizing traditional gasoline and diesel engines. Unfortunately for VW and the other German companies, the Toyota Prius converted all-important U.S. buyers to the hybrid doctrine. If Volkswagen wants to boost its share of the U.S. market, it needs hybrids, too.

One is coming. In February, Wolfsburg-based VW began previewing an advanced prototype of the company’s Touareg SUV featuring a hybrid drive. The car could be ready for production in as little as a year, joining a tiny but growing fleet of German hybrids that also includes a version of Mercedes’ luxury S-Class, due to go on sale at midyear.

The hybrid Touareg is doubly interesting because the car is a close cousin to the Porsche  Cayenne, with which it shares body design and many parts. Porsche will use the same technology as VW for a hybrid Cayenne, and took part in the development. The Touareg is also the forerunner of other hybrid Volkswagens.

Once German engineers set their minds to a task, they usually do it pretty well, and the VW hybrid team seems to be no exception. I had a chance to drive the Touareg hybrid prototype on Feb. 9 and was impressed both with the mileage and the performance.
A Full Hybrid Car

Unlike the S-Class, which uses its electric motor only to assist the gasoline engine, the Toureg is a full hybrid that can run solely on electric power at low speeds, though only for a mile and a half or so. The Touareg’s electric motor also provides an acceleration boost when needed, for example to pass a truck on the highway.

In fact, the hybrid Touareg will accelerate more quickly than any of the existing versions. VW says the prototype can go from zero to 60 mph in 6.8 seconds—though you certainly won’t get maximum fuel mileage driving that way. The hybrid Touareg can also pull as much trailer weight as the gas versions. “We wanted this Touareg to drive just as well as any other Touareg,” says Eike Feldhusen, one of the Volkswagen engineers who led the development of the hybrid. However, people who really use the car off-road a lot will probably want to stick with a traditional power train, which offers better power at low speeds.

The Touareg saves fuel in several different ways. The electric motor relieves the gasoline engine at low speeds, which is a particular advantage in city driving. In addition, the gasoline motor automatically shuts down when the car is coasting or stopped, restarting when you press the gas pedal. And the car recaptures energy normally lost from braking, with a mechanism that transfers the kinetic energy to the generator instead of the brake pads.
The Green Game

As I drove the Touareg on roads in and around Wolfsburg, it occurred to me that another one of the ways hybrids save fuel is by providing positive feedback to the driver. When you set off in the Touareg, a display right in front of the steering wheel tells you your average fuel economy. A second display, featuring a graphic of the power train, glows green when you’re using braking energy to recharge the battery, blue when you’re running on electric power alone, and ochre when you’re drawing on the gasoline motor, a 3.0-liter V6 adapted from the Audi S4.

After a while it gets to be a game. Just how much fuel economy can you eke out? How long can you run on electric power alone and get the display to glow green? (Normally the gas engine kicks in at about 10 mph, but VW engineers say they’ve gotten the car up to almost 50 mph on electric power alone, albeit on a very flat road.)

You become acutely aware of how your style of driving affects fuel economy. With the Touareg, slow acceleration gets the most out of the electric motor, while slow braking is the best way to regenerate power. As a light-footed driver—my daughter always complains that I’m hopelessly pokey—I did pretty well. After about 45 minutes in Wolfsburg traffic and country roads outside the city, with lots of starting and stopping, the meter told me that my average fuel economy was 8.4 liters per 100 kilometers, or 28 mpg.
Eight-Speed Automatic Transmission

The VW engineer riding shotgun told me that was a good score, but maybe he was flattering me. That’s about how much fuel consumption Volkswagen hopes to achieve under normal driving conditions for the production version, which will be lighter than the prototype and thus more efficient. If so, fuel consumption of the hybrid will be 30% better than the existing Touareg gasoline V6, and 8% better than the most efficient diesel version.

The only flaw I noticed in the Touareg was the shifting of the eight-speed automatic transmission. Gear changes were pretty noticeable, in comparison to the nearly imperceptible shifting of the Mercedes S-Class I drove last year. But engineer Feldhusen says the clunkiness will be ironed out in the production versions after developers tune the transmission more closely to the hybrid power train.

Volkswagen hasn’t decided when to start selling the Hybrid Touareg. But if the marketers decide that demand is there, VW will be ready to mass-produce the car early in 2010, which could mean a U.S. launch by the middle of that year. The final price will depend a lot on how much Volkswagen winds up paying component suppliers such as Bosch. But hybrid buyers can expect to pony up a premium over the existing Touareg, which lists at $39,300 in the U.S. For now, at least, going green has a price.

Source: BusinessWeek

Leave a Reply