Meet the VW Formula XL1 concept, the latest vehicle in VW’s line of ultra-efficient, one liter vehicles. Unveiled at this weeks Qatar Motor Show (which seems like an odd place to promote fuel efficient vehicles), the Formula XL1 pulls out all the stops to boost fuel economy and reduce emissions. A plug-in hybrid, the XL1 is powered by both an 800cc, two cylinder TDI engine and a lithium-battery-powered electric motor. Combined, they give the car an astonishing 260 mile per gallon fuel economy, yet still yield reasonable performance. Zero to one hundred kilometers per hour (62 MPH) takes 11.9 seconds, which is on par with some of today’s more fuel efficient vehicles. You won’t be autocrossing the XL1, but cars like the XL1 may allow you to continue autocrossing your fuel-gulping Mustang GT.
With a full charge of the batteries, the XL1 has a range of approximately 21 miles in electric mode. When the batteries are depleted, the car switches over to TDI power via “pulse starting”, which uses the electric motor to spin the TDI engine to the appropriate RPM before engaging it. For maximum acceleration, the electric motor can be used in parallel with the diesel engine, and drivers can select which mode they choose to operate in. Light weight is key to the XL1s fuel efficiency, so the car relies heavily on the use of carbon fiber reinforced polymer (CFRP) for both the body panels and the monocoque. The net result is a curb weight of just 1,750 pounds.
Aerodynamics play a large role as well, and the XL1 has an ultra-low drag coefficient of .186. By comparison, a VW Golf has a drag coefficient of .312, while the sleek new Hyundai Elantra has a drag coefficient of .28. Volkswagen claims that the XL1 is the most aerodynamic vehicle in its class, but I’s be reasonably comfortable in calling the XL1 the most aerodynamic vehicle in any class.
Unlike previous one-liter concept vehicles, Volkswagen has announced a limited production run of the XL1. Up to 100 cars will be built for select markets, with production beginning in 2013. VW won’t even speculate on markets and pricing, but I’d be very surprised to see the car in the United States. As for price, carbon fiber monocoque vehicles don’t come cheap, so my best guess would be somewhere in the low six figures. Whether or not the XL1 will see significant production numbers is somewhat irrelevant; what is relevant is the amount of technology developed for the XL1 that will trickle down into other production Volkswagens.