TwinDrive VW Golf a "different sort of hybrid"

Volkswagen's TwinDrive Golf is a zero-emission electric car first and a hybrid second... And it could be on sale within three years! Least that was the company line from a key Volkswagen exec at last week's international launch of the Golf VI in Iceland.

The TwinDrive was displayed as a mock-up -- a standard Golf VI with Twin Drive signage and a false mains power charging plug -- at the million-dollar mountain-top Golf launch headquarters near Reykjavik.

The vehicle is effectively a placeholder for Volkswagen's entry into the electric car frenzy that starts in earnest in around 18 months when, because of new state laws, manufacturers must offer zero emission vehicles (ZEV) to remain competitive in the lucrative Californian market. In its own right the US state is one of the biggest new car markets in the word.

Volkswagen claims the TwinDrive bypasses the need to manufacture, pay for and lug around two separate drivetrains. The concept pairs a battery-powered electric motor with a single-ratio automated manual gearbox. A conventional combustion engine is used as a range-extender and/or performance-booster, but is connected to the motor-gearbox combo by a user-actuated clutch. The German car giant calls the system, e-Drive.

The vehicle can use a single-ratio gearbox (around the equivalent of fifth gear in a 'normal' Golf) because of the high torque output of the electric drivetrain.

According to Volkswagen Executive Vice President, Detlef Wiitig, the TwinDrive is "more into the Volt direction than into the Prius direction.

"You don't have to pay for two engines," he told the Carsales Network.

Volkswagen says the current TwinDrive architecture will deliver around 50km range, at urban speeds. Volkswagen is 'selling' the TwinDrive as a vehicle in which the owner can choose to employ the non-electric part of the powertrain, or supplement the above performance by using the conventional engine.

Volkswagen says owners will charge the TwinDrive from the mains between journeys. However, just like the conventional hybrids (from which Volkswagen is adamant TwinDrive differs), the coupled combustion engine can charge the TwinDrive's battery. Regenerative braking is also used to top-up the battery pack.

"The operation [of TwinDrive] is different. Hybrid, the way the Japanese do it, is sort of integrated to a certain extent and is automatically switching from this and that. You can run the TwinDrive on electric engine only... For 50km and then its over, but you can run it to your own disposition at zero emissions," Wittig opined.

Consumer trials of the TwinDrive commence next month in Berlin where up to 30 vehicles will be placed with government and private consumers. The trials are ongoing.

But Wittig says a mass-produced TwinDrive Golf will be on sale within the model life of the new Golf VI.

In "two to three years," he says customers will be able to buy a TwinDrive Volkswagen.

According to Wittig, it is the vehicle's electric-only range that is keeping it from market. He says the carmaker is working on battery and drivetrain development with "non-automotive" German and Japanese partners.

"For us the challenge is to improve the efficiency of the batteries - battery technology is the key... This [generation] runs for 50km which is not sufficient. When you go for city driving and the ladies go shopping and so forth and so forth, 50km is something that is scary, but 100-120km would do it. That's the target," Wittig explained.

"There are interesting battery technologies on the way and that is what we are working on.

"We are not in [this] for a marketing purpose. We want to have a serious thing. We want to make money and not, sort of, subsidise. And we don't want to steal money out of the pocket of the consumer.

"The objective is to have a car that is in mass production that could replace someday gasoline or diesel engines and it all depends on the battery technology," Wittig said.

"There is so much research being done by various companies which is different from what we see in other parts of the world -- that you don't see from General Motors or various [other companies] and this is promising... Very promising," Wittig opined.

Says the VW sales boss, no firm decision has been made on the combustion engine technology that will partner the electric powertrain in the production TwinDrive, however.

"[TwinDrive] Is a further addition to our range [of drive technologies]. As far as combustion technology is concerned we can do it with smaller TSI gasoline engines or smaller TDI diesel engines - this part is coloured by ourselves. The battery technology we have to partner with specialist companies."

According to Wittig, both petrol direct-injection TSI and common-rail TDI turbodiesel TwinDrives would deliver an equivalent 'averaged' fuel economy of 2.5L/100km.