Posted on March 12, 2017 by Charles Morris
Taking a few hot laps on the world-famous Nürburgring is a dream come true for any car lover. It’s actually not an unattainable dream - the track hosts regular rallies that are open to the public. When amateur race drivers Roland Schüren and Uwe Koenzen took Roland’s Model S 85D to the Nürburgring Nordschleife, they weren’t there for a typical Sunday drive - their goal was to test the Tesla’s efficiency on a long and demanding course.
Roland and Uwe have been part of the electric vehicle (EV) scene since long before it was cool - in 1995, they converted a 1967 Porsche to electric drive. Uwe’s company, Broedersdorff & Koenzen classic eCars, builds EV prototypes and develops battery technology. Their latest product is the eSchmitt, an electric version of a classic old Messerschmitt, which they claim is the world’s most efficient street-legal car (energy usage is 3.7 kWh/100 km).
The two went to Nürburg to take part in the GLP Regularity Race. The goal of this event is to finish 12 laps - a total of 250 km - as close as possible to a self-defined time. You can drive as fast or slow as you wish - the object is to estimate your total time as accurately as possible. Sound easy? It’s not. The Nordschleife is not only curvaceous, but very hilly. Its notorious difficulty led driver Jackie Stewart to dub it “The Green Hell” following his victory in the 1968 German Grand Prix.
“We were alone with the Model S among 140 internal combustion engine cars, fitted with roll cages, wide track tires,” said Uwe. “The other teams were really interested in our experiment. They asked us a lot of questions. We didn't expect so many positive reactions.”
Crashes and breakdowns are so frequent during these public rallies that all cars are required to have towing brackets fitted, so that tow trucks can quickly remove disabled vehicles from the track. “On the Model S there’s no easy way to attach these rings, so we fastened straps to the chassis,” Uwe explains. “For that we have to thank Black Falcon Racing, a well-respected long-distance racing team.”
As every Formula E fan knows, the limited range of an EV adds a new dimension to racing. “There is lot of discussion about Model S on racetracks, mostly focused on the short time performance. But we would like to know what will happen on a distance of more than 250 km on a very hilly and difficult racetrack,” explains Dr. Uwe Koenzen. “The special challenge with a Tesla is to drive fast and efficiently.”
Now, for those of us driving our EVs around town, driving fast and driving efficiently are seen as mutually exclusive - you can zip around and have fun, or you can carefully “hypermile” and maximize your range. A race driver, however, must learn to do both at the same time.
The two German engineers rose to the challenge. “We did a very accurate calculation which takes into account the complex topography of the Ring. We finished with only 5 km of power left in the battery - our calculations and driving matched perfectly.”
Roland and Uwe achieved an average efficiency of 268 Wh/km, which translates in gas-mileage terms to approximately 3 liters per 100 km (about 78 MPGe for US readers). “That is surely an efficiency record,” says Uwe. “Sedans in the same weight class use around 12-15 liters/100 km for these lap times.” Their top speed on the downhill stretches was about 190 km/h (118 mph).
*Special thanks to Roland Schüren and Uwe Koenzen for reaching out to us to relay this fantastic story along with such stunning photos. To learn more about their adventures (and work) in the electric vehicle space, visit: www.classic-eCars.de