Manufacturing Electrified Vehicles in Wolfsburg

The Volkswagen plant in Wolfsburg, Germany, is said to be the world’s single-largest car manufacturing complex in the world. Given that it is located on an area greater than six square kilometers (and we learn that you can actually get traffic tickets within the gates of the complex, and if you’re one of the ~57,740 people who work there, you don’t want that to happen, not only because of the cost, but because the ticket goes into your personnel file) and that the combined under-roof footprint of the manufacturing halls is 1.6 square kilometers (which a VW spokesperson points out could cover the entire Principality of Monaco, although it is worth noting that while the Wolfsburg plant is on the banks of the Mittellandkanal, an artificial waterway, and Monaco is on the French Riviera, so we give it to Monaco on that score), that claim is probably legitimate.

The Wolfsburg plant was completed in 1939. Then World War II changed the nature of what was built there. It became the home of the Beetle after the war. Beetle production ended in the plant in 1974. Wolfsburg produced 11,916,519 Beetles during its run. The successor to the Beetle is the Golf, which went into production at Wolfsburg in 1976 (yes, the Beetle continues to exist, but the Golf is its mass-manufactured successor in the company’s lineup).

In 2013, some 807,000 vehicles were manufactured in Wolfsburg, including the Golf, Golf Sportvan, Touran, and Tiguan.

And there were, and are, two more models that are now also being built in Wolfsburg, exceedingly contemporary models in a plant that is designated a historic landmark in Germany: the Golf GTE and the e-Golf.

Yes, the “e” in both case signifies “electric,” with the first being a plug-in hybrid and the second a full electric vehicle.

Dr. Harald Manzenrieder, head of e-Golf production at the Wolfsburg plant, points out that VW has had experience producing electric vehicles for some time: “We didn’t start yesterday,” he says, pointing out that back in the 1970s they built an electric-powered T2—better known in the U.S. as the VW Microbus. But that was essentially a research project. VW actually put an electric Golf on the German market in 1989, the Golf CityStromer, based on the second-generation Golf; it had a 18.5-kW AC motor and was powered by 16 lead-gel batteries.

Again, a low-production vehicle.

But with European Union regula-tions calling for significant cuts in CO2 emissions, Volkswagen Group—meaning the whole organization, including Audi and Porsche—is undertaking a serious endeavor to produce vehicles that have electric or electrified powertrains.

And the Wolfsburg plant is a center of gravity for those activities, with the eGolf and the GTE.

“When we started to bring the e-Golf into mass production”—it went into serial production in March 2014—“one of our main concerns was worker safety,” Manzenrieder says. So they insti-tuted a training program with three levels of certification, with the most basic being the ability to assemble and handle parts; the middle level being those who can deactivate the high-voltage systems in the vehicles (e-Golf or GTE); and the top level—of which there are just 7 people qualified for—who can work on the vehicles under power. The intent is that these specialists can not only build cars, but actually train not only other 
people at Wolfsburg, but those who work in Ingolstadt or Stuttgart. 

It is a center of competence.

“A Golf is a Golf,” Manzenrieder says, explaining that because of the MQB architecture that underpins the vehicle, it can be a 300-hp Golf R or an e-Golf that goes down line #3 in Wolfsburg, a line that has a capacity of more than 1,100 vehicles per day, in any mix. “This is an assembly-friendly car,” he comments. “We can fully build the e-Golf in line, but at this stage, we have decided to use a bypass.”

Essentially, the e-Golf is produced on line, including the electric motor (85-kW; built in the VW Kassel, Germany, components plant). “The car is built as a rolling chassis, with the electric motor,” Manzenrieder explains. They tow it to the bypass area, where two workers are assigned to a vehicle. They build the front end components and electrics, then put the car on a lift so the battery pack (27 modules consisting of 264 lithium-ion cells; built in the VW plant in Braunschweig) can be installed and underbody paneling added.

Once the battery is installed and the vehicle started, the e-Golf goes back to join the variants with gasoline and diesel engines. As well as the GTE (60 workers have been trained to build the hybrid variant). “The workers pack their own shopping carts so they know each bolt, each cable, each component,” he says, adding, “This results in the creation of real experts.”

While the number of e-Golfs produced with the bypass system is comparatively small—about 22 cars per shift—Manzenrieder stresses that there are a few benefits in this still-early stage. “Once the car is at the quality gate, we don’t need to feedback to a big team, but directly to the worker.” Product changes can be readily accommodated.

And, most importantly, “It is still kind of a training area now. We cooperate with colleagues from other production sites, and other group brands,” he says. The plan is to leverage the learnings throughout the group.

The Hot Hatch Goes Hybrid

The Volkswagen GTI is the car that gave meaning to the term “hot hatch.” The car features a 2.8-liter, turbocharged, direct-injection engine that produces 210 hp and 258 lb-ft of torque, which is up 10 hp and 51 lb-ft lighter than the previous-generation model. Factor in that the car is 81 lb. lighter than its predecessor—predicated, in part, on the fact that they’re using 28% high-strength and hot-formed steels, up from 6%, and that they’re using tailor rolled blanks for some of the components, blanks that in some cases have 11 zones of varying thicknesses so that the strength is optimally located—and you can get the notion of how the basic power-to-weight ratio is improved.

But replace the powertrain with another setup that combines a 1.4-liter, direct-injected turbocharged engine that produces 147.5 hp, a 75 kW electric motor, and a six-speed direct shift gearbox (DSG), an arrangement that provides a total system horsepower of 201 hp, and you have a plug-in hybrid that can accelerate from 0 to 62 mph in 7.6 seconds, yet has an all-electric range (on the New European Driving Cycle, NEDC) of 31 miles and a total range of 583 miles.

And what’s all-important in Europe for this car is that it has emissions of 35 g/km.

The 1.4 TSI engine was engineered for the application. For example, it is light, weighing just 226.6 lb. Because of the potential that the car is operated primarily on electricity (say someone has a 15-mile one-way commute; as a default—dependent on the state of battery charge and the outdoor temperature—the car starts in “E-mode,” meaning electric, so 
with a 31-mile all-electric potential, it could go and come without an engine start), they have done things like using polymer coating on the main and connecting rod bearings and hard coating the piston rings to facilitate performance when the engine kicks in. The exhaust manifold is integrated into the cylinder head so that the engine reaches optimal operating temperature quickly; the design also allows the use of a single-scroll compressor in the turbocharger.

The three-phase, 75-kw permanent magnet synchronous motor (built by VW, incidentally) is mounted on the input shaft between the dual-mass flywheel of the disengagement clutch for the engine and components of the transmission; it is integrated in the six-speed dual clutch transmission housing (there are actually three clutches, two for the transmission itself and the disengagement clutch). To integrate the motor into the gearbox the internal combustion engine is shifted 2.3 in. to the left (when looked at from the front). 

The GTE features a liquid-cooled lithium-ion battery pack that consists of eight modules. The energy capacity of the battery is 8.7 kWh.

The VW GTE is a plug-in hybrid so it has a plug-in port behind the VW badge on the grille for public or at-home charging and, as you will notice on the rear quarter panel, a fuel door for the 11-gallon fuel tank.

 

 

The powertrain system for the GTE: the 1.4-liter direct-injected, turbocharged engine; six-speed dual clutch transmission; 75-kW three-phase, permanent magnetic electric motor.