Electric Sunshine

Ruf's gasolineo-free Greenster meets its targa-topped forebear: Can a roofless, electric 911 provide the same thris as a carbureted piece of history?

August 31, 2009
Ruf's Greenster 1
Ruf Greenster 2
Ruf Greenster 3
Ruf Greenster 4
Ruf Greenster 5
Ruf Greenster 6
Ruf Greenster 7

Until recently, electric cars were emotionless, utilitarian devices. Green machines have traditionally traded on eco-friendly looks, so it’s no surprise that car enthusiasts have long seen electric vehicles as little more than soulless appliances. But when the Tesla Roadster and Ruf’s eRuf concept broke cover, enthusiasts took notice.

“The eRuf Concept Model A was a purely experimental car, one we used to explore the technology available at the time,” Alois Ruf says, admitting that the finished car was far from ideal. Battery technology kept the project from being as capable or practical as he would have liked, but that was part of the plan: “We knew that we would benefit from technology advancements a year or two down the road,” he says.

Enter the Ruf Greenster, the next evolution of Ruf’s electric-car thinking. The Greenster is the second-generation Ruf electric, both in terms of design and technology. After establishing maximum-range parameters with the Concept Model A, Ruf approached the design of the Greenster with a view toward making it both more elegant and more user friendly, as well as more of a production model. Fittingly, the car will see limited production — in the coming months, Ruf plans to complete up to 20 examples.

At 3,638 pounds, the Greenster is 551 pounds lighter than the Concept Model A, and it retains the 911’s forward luggage compartment. (The Model A sacrificed that luxury for increased battery capacity.) “One of the ideas behind the Model A was to see how much range we could squeeze from the batteries,” says Ruf. “With 51 kilowatts of batteries, this turned out to be 300 kilometers, dropping to 150 kilometers in hard use. By comparison, the Greenster carries 31 kilowatts and has a range of 250 kilometers. Drive it like a Porsche, and that figure drops to around 120 kilometers.”

The Greenster also departs from the Model A mold in one very significant way: It does without a manual transmission. “The electric motor has so much torque,” explains Ruf, “that it simply does not need six speeds. We saved 198 pounds by deleting it.” A single ratio and a mechanical differential replace the six-speed transaxle used in the Model A, and batteries occupy some of the newfound space. A small battery pack also sits in the area normally occupied by the fuel tank. Weight distribution remains similar to that of an ordinary Carrera.

As it stands, the reduced range of the Greenster is fine for urban use or a pleasure drive, but as with the Model A, the batteries take six hours to recharge from empty. “Our battery supplier, Sie­mens, is exploring faster charging systems,” says Ruf. “High-amperage charging systems like the one used by the Mini E are garage-based, and we want to have a compact, on-board charger that you can simply plug into the wall at home or at work.”

This is all well and good, but what of the roof? What of the body? How did Ruf produce a true, roll-bar-equipped targa? Easy: He did the same thing Porsche did when it built its first Targa — he used the shell of a 911 coupe as a starting point.

Also from Issue 176

  • 908/3 Driven on the Street!
  • First RHD 356 Coupe
  • Spec 911. vs. GT3 RS vs. GT3 Cup
  • 2007 911 GT3 RSR on track
  • The Fourth Glöckler
  • Infamous Mulholland 911 Street Racer
  • 170-mph 924 Autobahn Sleeper
  • Market Update: 1999-2007 911s
  • Porsche Icon: 550
  • Project Cayman: An Introduction
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