With a six-foot eight-inch, 264-pound driver and a route with three alpine passes, Volkswagen's new one-liter car fell short of its lofty fuel-economy claims by about 50 percent, netting "only" about 160 mpg. Nonetheless, the XL1impressed on this first drive, as the mid-engine two-seater proved to be both superefficient and a hoot to drive.
Shiny, low-drag carbon fiber surrounds us, and the picture-postcard panorama looks slightly distorted through the thin polycarbonate windows. Behind the seats and rear firewall two surprisingly vocal propulsion units are at work, sometimes separately, sometimes in unison.
This is not your father's Vee Dub. Powered by a 47-hp, two-cylinder diesel in conjunction with a 27-hp electric motor, it's expensive and exclusive and breaks with tradition in every important respect. The scissor doors will blow open via integrated pyrotechnic devices should the car ever come to rest on its roof after an accident. To accommodate the ultraslim nose and to keep the driver and passenger from rubbing shoulders, the two bucket seats are staggered. Instead of mirrors, full-color monitors integrated in the door panels depict the rearward view. The only low-tech items inside are the window cranks.
Our six-hour tour takes us from Lucerne to Geneva and includes a challenging mix of city traffic, autobahn, back roads, and steep climbs and descents. In town, the 1753-pound eye-catcher unleashes 103 lb-ft of clean-energy torque whenever you depress the accelerator. The range indicator, the state-of-charge display, and the fuel gauge reflect every passing maneuver. Unassuming pedestrians step into our flight path because they do not hear the whispering two-seater approaching from behind. Inside the beautifully finished, cocoonlike cabin, the XL1 makes strange noises. The carbon-ceramic brake discs rumble and chafe when used lightly, the suspension responds to potholes with random thumps and plops, and under trailing throttle the transmission sounds like a coffee grinder.
"One-liter car" is Euro-speak for the gold standard of green driving; a car that consumes one liter of fuel in 100 kilometers, or the equivalent of 235 mpg. VW actually claims 0.9 liter per 100 kilometers (261 mpg) for the XL1. Mind you, these figures come from standardized European testing, which typically yields results that skew higher than U.S. fuel-economy ratings. The Toyota Prius, for instance, gets a combined rating of 3.9 liters per 100 kilometers (60 mpg), whereas the EPA rates the car at 50 mpg combined.
In theory, the XL1's 5.5-kWh lithium-ion energy cells provide about thirty miles of electric-only driving. In reality, it is almost impossible to maintain the steady pace required to reach this goal, so it's advisable to switch to hybrid mode as soon as the speed quickens and whenever there are mountains to climb. The two-cylinder diesel cuts in and out with pursed clutch plates, but -- especially when still cold -- its working noises sound like an air hammer trespassing in a library. Braking smoothly takes practice because the transition from recuperation to deceleration can be rough. That said, we barely have to touch the brake pedal in an hour of driving, preferring instead to lift off the accelerator and coast where possible: the XL1 is a clear case of fuel economy by foresight. Although the consumption readout should be the pivotal gauge in a one-liter car, our eyes are glued to the state-of-charge indicator. In this environment and in this kind of car, every climb is your worst enemy, every descent your closest ally.
After 135 miles in test car number three, the trip computer reports the equivalent of 147 mpg, an average speed of 23 mph (which, even for Switzerland, is very slow), and 127 miles of range remaining. This isn't the whole story, because my consumption hovered around 118 mpg in test cars one and two, excellent for a two-seater that can top 100 mph but below par among a competitive group of pussy-footers. I share with the eco pros the unexpected fascination of slow speed, the joy of changing direction with unassisted steering, the brakes' dual role as energy generator and energy annihilator, a new perception of the accelerator -- which is progressive to the point of feeling lazy yet totally instantaneous -- and, of course, the dynamic kick of a mid-mounted plug-in powertrain driving the rear wheels. There is also the eerie pleasure of mingling with dedicated mpg junkies who automatically switch off the heat and air-conditioning, won't defog steamed-up windows or listen to the radio, and avoid switching on the headlights in tunnels.
We never test the 12.7-second 0-to-62-mph claim and never see more than 78 mph on the digital speedometer. Only once does the devil inside take over and make Herr Engineer in the passenger seat unhappy for the rest of the day. His dream of winning the efficiency trophy is over after I stretch my right foot in the direction of Geneva, kickdown from seventh gear into fourth, then pass three cars in a row with the angrily snarling engine yelling "yippee!" through that sleepy valley. The steering is honest and keen, the chassis is firm and stable, the brakes are prompt and well balanced, the skinny tires have more grip than their small contact patches suggest, and the engine and electric motor are really something when they fuse power and torque. The wheelbase is long enough for decent directional stability on fast straights and short enough for carving through hairpins and waltzing through esses. It would have been wonderful to maintain that brisk Tour de Suisse momentum, but the numbers on the in-dash monitor suggest otherwise: 156 mpg, 9.5 percent state of charge, EV mode not available. A guilty conscience sits heavily on my shoulders for the rest of the trip to Geneva. When we reach our final destination, the XL1 consoles itself first at the pump and then at the wall charger. Thanks for the drive, my friend. No hard feelings.
VW's one-liter car shows what can be done when brainpower and money are no object. Although the XL1 may indeed be limited to 250 units with no plans for U.S. sales, the related XR1 (see sidebar) could find more takers. The plug-in-hybrid powertrain, however, has what it takes to become the affordable alternative drivetrain of choice across most of the model range. The two-cylinder plug-in will debut in 2015 in the Up!, a three-cylinder version is earmarked for the 2016 Polo replacement, and a four-cylinder plug-in will be offered in the seventh-generation Golf before the end of 2014.
A hypermiling sports car
How the XL1 might morph into the spicier XR1.
The 261-mpg XL1 is too high-priced and too low-volume for Volkswagen to federalize it for U.S. sale, but a sports car based on the same structure might just make it here -- if it gets built at all.
The XR1 is conceived as a high-tech, carbon-fiber sports car that would offer Porsche 911 performance (and hybrid fuel economy) for half the money. To hit that price target, VW would need to use a parts-bin engine. Fortunately, the company has very well-stocked shelves. Potential engines include the seventh-generation GTI's 220-hp, 2.0-liter turbocharged four-banger and a turbo- or supercharged three-cylinder of 1.2 or 1.4 liters.
"A four-cylinder looks like the most promising option," states our friendly board member. "It is hardly bigger, not much heavier, and barely more expensive to produce than a three. It gives us more options in terms of power and torque. Its part-load consumption is actually quite low. A new seven-speed dual-clutch automatic good for up to [250 lb-ft] of torque would be the perfect match for this engine."
This would obviously hurt fuel economy, but VW still believes that the XR1 can achieve 70 mpg. Removing the XL1's battery pack and electric motor would cut 230 pounds from its 1753-pound curb weight, but to save money engineers would add some of the weight back by using aluminum instead of magnesium wheels, steel brakes in place of carbon fiber, and glass rather than polycarbonate side windows. The XR1 would get a wider, more comfortable monocoque, and the front and rear tracks also would be widened.
"Removing the rear wheelhouse fairings gives the car a more aggressive look," says a source familiar with the project. "The wider track yields a sportier, Coke-bottle plan view. The scissor doors work equally well on a fuel miser and on a sports car. The redesigned front and rear will completely change the character of the car. The performance version loses a couple of points in the wind tunnel, but it looks meaner."
The XL1's drag-cutting, camera-based sideview mirrors cost only about $250, so there is no reason they should not reappear on the XR1. However, they might cause a snag with federal regulators. Whether the XR1 will gain a rear window depends on its design philosophy. Competing design concepts reportedly include a low-drag teardrop silhouette with an integrated active spoiler and a high-downforce Kamm-back design, either of them with LED headlamps and taillamps and sixteen- or seventeen-inch wheels with lower-profile tires. Like most modern sports cars, the XR1 would feature an adaptive suspension.
Although Porsche is part of the VW Group, the target is to beat the 911 for acceleration, top speed, and fuel economy. VW's bean counters must cooperate by approving the groundbreaking two-seater for less than $50,000. The project has not yet been formally approved.
All this suggests an 1875-pound two-seater that can sprint to 62 mph in less than 4.5 seconds, reach a top speed of almost 190 mph, and achieve 70 mpg. The asking price depends on volume at VW's Karmann plant, which is currently geared to assemble 1000 carbon-fiber vehicles per year.