CHUCK SQUATRIGLIA, Autopia at Wired, June 12, 2008
Although the company was also showing off its upcoming diesel Jetta TDI and talking a lot about the TDI Cup diesel racing series it sponsors, the Tiguan HyMotion was clearly the star of the show. It’s an advancement over the HyMotion Touran it replaces, but company officials made it clear they aren’t betting on hydrogen alone to save us.
“There isn’t one technology, one fuel, that will provide the answer,” John Tillman, who leads VW’s advanced powertrain division in the U.S, told Wired.com. “We have multiple technologies. This is just one of them.”
The company is pushing clean diesel in a big way and expects it to comprise 30% of its sales within a decade. But, like a growing number of automakers, it believes “the electric motor is the ideal prime mover for sustainable economy,” and Tillman says VW is working on hybrid and battery electric drivetrains.
Volkswagen’s been playing with fuel cells for 10 years now, and it launched a dedicated fuel cell and EV research center in 2001. The Tiguan HyMotion is its fourth generation FCV and the its most advanced.
The proton exchange membrane fuel cell generates 80 kW, but it’s coupled with an electric motor and lithium-ion battery that bump output to 100 kW (about 134 horsepower). That’s enough to propel the Tiguan, which weighs about 4,122 pounds, from zero to 60 in 14 seconds and a top speed of 93 mph. Not great, but better than the Touran’s 86 mph. The battery has a charge capacity of 6.8 Ah and is charged by the fuel cell and regenerative braking. The HyMotion also uses stop-start technology to reduce fuel consumption.
Besides their astronomical price, one of the shortcomings of fuel cell vehicles is their range, and the Tiguan offers a relatively paltry 160 miles. It carries 3.5 kilograms of gaseous hydrogen in a tank made of carbon fiber, kevlar and aluminum at a pressure of 10,000 pounds – twice that of the Touran. “We could go higher, but who’s going to provide the fueling infrastructure at that pressure?” said Westley Khin, one of the engineers who worked on the car.
Ah yes, the fueling infrastructure. The Achilles heal of fuel cell vehicles, along with the astronomical cost of the cars themselves. Khin concedes both are the big stumbling blocks to the commercialization, but says “the vehicles are here” and they work well. That may be, but VW’s only built two HyMotion Tiguans and doesn’t have any plans to start putting them in driveways like Honda’s doing with the FCX Clarity.
“The FCX Clarity is a good vehicle. But we want to introduce a vehicle when the customer has the capacity to fuel it. We don’t see that happening anytime soon,” Tillman says, adding that VW is “working on developing” a home-hydrogen station along the lines of what Honda’s got.
By the way, we asked Tillman if there’s any chance we’ll see that sweet 71 mpg diesel-electric Golf hybrid VW unvieled earlier this year at the Geneva Motor Show. “We’re looking at it. I don’t have a timeline, but we are looking at it,” is all he’d say.
VW realizes there’s a market for the car but says the problem is making it affordable. Hybrid drivetrains are expensive – they add about $5K to the sticker price. So are diesel engines, which cost about two grand more than similarly-sized gasoline engines. Put them together in the same car and things quickly get expensive. “We have to get it to a price point that people can actually afford,” Tillman said.