Thursday, February 17, 2011

Driving report of the Volkswagen XL1



This might become another future car we are promised but never get, but one quick drive reveals this much: The Volkswagen XL1 is a real car, nearly as tangible as a Chevrolet Volt.

Lift the gullwing door, step over the wide inside rocker panel, and you settle into a comfortable seat with a wide, curved windshield and decent-size door windows with tollbooth access. Hit the starter button once without a foot on the brake pedal (real as the car feels, it isn't federalized, here or there). Blip the throttle and then put a foot on the brake and hit the start button again. From here on, any auto journalist who has driven any number of cobbled-together concept cars will realize the XL1 is remarkably complete. With switchgear you'd recognize from any late-model Golf or Polo, it feels like a factory-fresh car.



Slip the gearshift into "D." You can't sequentially shift the seven gears, because VW is pushing maximum efficiency. Let off the non-assisted brakes, tip in carefully, and the VW quietly, gracefully eases out from the hotel driveway into a nearly empty street. It's 8:30 a.m. on a Saturday in Doha, Qatar, and the stunt car drivers who make up the local populace are on busier streets a few blocks ahead. The XL1's entourage includes a Toyota Land Cruiser cop car, a VW CC, and a Touareg camera car leading, and another Touareg covering the XL1's backside.

There's no rear window. The 74-horsepower plug-in hybrid midship powerplant, consisting of a lithium-ion battery-powered motor, a 0.8-liter two-cylinder turbodiesel (half the 1.6-liter TDI) with a much-needed balance shaft, and a seven-speed dual sequential gearbox (DSG) is in back, driving the rear wheels. While the fender-skirted two-door bodystyle recalls the GM EV-1 from some angles, the roof panel where the rear window would be is right off the Tatra T77. Sideview mirrors are tiny cameras halfway down each gullwing door panel, with video screens fairly low at the leading edges of the interior outboard armrests to reduce glare. They're effective, and VW engineers will speak hopefully about changing safety laws, but it's good to have that Touareg covering in back.





Steering is very direct, with great feel and feedback, because like the brakes, it's not power-assisted, saving weight. At 1,753 pounds and with hard, low rolling-resistance tires, p/s is unnecessary. The double-A-arm front, with carbon-fiber anti-roll bar and semi-trailing arm rear suspension is stiff, although on Doha's recently poured, smooth roads, it doesn't seem too harsh to anyone familiar with traditional sports car ride quality. Just from taking Doha's roundabouts at safe city speeds, it feels like it would be a good handler, if the stiff tires didn't give up so easily. The tires betray a lot of road noise in this virtually insulation-free car.

Kick down the throttle for more power, and the TDI starts up with the kind of rumble you might remember from a Rabbit diesel. It quickly becomes unnoticed, though, and actually adds to the feel that you're engaged with the car. Subsequent transitions to and from the diesel feel more seamless, and the 7-speed DSG is the perfect transmission for an extended-range plug-in. The mechanical brakes certainly need more boot than most power-assisted units do, though that same "engaged" driver won't complain. Problem is, the average driver will, if it's even legal to build a car without power brakes these days (an XL1 update will replace the steel brake calipers with carbon-fiber).

Acceleration is spritely, which "feels quicker than it is." VW says it'll do 0-62 mph in 11.9 seconds. Top speed is electronically limited to 99 mph.

VW began its 1-liter car program in the late 1990s, and built its first to achieve 1-liter/100 kilometers fuel consumption in 2002. A 2009 show car called L1 retained the '02 model's 1+1/tandem seating arrangement, but hinted at the XL1 two-seater's styling. In the XL1, the passenger seat is set 10.9 inches back from the driver's seat, and doesn't get the driver's seat's fore-and-aft and seatback angle adjustment. The driver also gets a tilt-and-telescopic steering wheel that contains the car's only airbag.

As if that won't discourage production, there's obviously very high cost in the XL1. VW says replacing the carbon-fiber body panels with aluminum would increase weight 20 percent, while steel would boost it 30 percent. An extra 350-500 pounds would be far too much for its 47-horsepower I-2 TDI and its 27-horsepower electric motor. Torque totals 163 foot-pound, 74 from the motor and 89 from the TDI.

The good news is that VW's patented carbon-fiber production process (Porsche F1, Herr Piëch?) makes it possible for the company to build 24 XL1 monocoques per day. And the carbon-fiber construction and electronic stability control should allay any fears about the XL1's small dimension - it's 153.1 inches long, 65.5 inches wide, and 45.5 inches tall.

VW says the XL1 consumes just 0.91 liters of diesel per 100 kilometers, the equivalent of about 260 mpg. The battery is good for up to 22 miles of pure electric-powered driving, with total range of 332 miles before filling the 2.64-gallon tank (yes, that averages out to 125.7 mpg). Better yet, VW says the XL1's 360-volt recharging box (the same capacity as many washing machines) can fill up the battery in 30 minutes. A 240-volt recharge takes an hour.

The prototype was built without some safety and comfort features, such as the ESP. VW engineers' next task in this ultra-intensive program is to see what can be added, where more weight savings might exist, and keep consumption under 1 liter/100 km.

So what's the problem? Even with the patented process, rendering a car in carbon fiber costs about 20 times as much as steel, VW says. That would make this plug-in sports car far more expensive than the Chevy Volt. Still, VW engineers keep talking about the XL1 in terms of a production version. It could begin with a small production run, to prove VW can do it, and maybe provide a city car for Bugatti owners



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