For the world’s automakers, there is a new race. There is no track, and no finish line except to drive as far as mechanically possible on one gallon of gas (or its electrical equivalent). The latest champion, it seems, is Volkswagen. It’s a new limited production sports car, a diesel plug-in hybrid called the XL1, is claiming a record-breaking 256 MPG. Fifty of the cars priced at 100,000 Euros will start hitting German streets later this year.
"This is our Formula 1," VW Group’s former chief, Ferdinand Piëch, told Car and Driver about the XL1 after driving one of the earlier prototypes. The company, which also owns Audi and Bentley, is engineering for radical efficiency, not just racetrack speed. Like other companies, its inspiration is now pushing the limits of fuel efficiency. Now, if VW can build the most fuel efficient in the world, said Piëchs, "we always win."
But the "one-liter" car has been a long time in the making. as a car capable of driving 100 km on just one liter of gasoline (261.4 mpg), the XL1 has taken decades to develop in fits and starts. Early prototypes were balky and uncomfortable, but rapid advances in materials and electric hybrid technology have turned a unrealistic vision (Piëch even said in 2002 that "we will never build a 1-liter car" thinking a 2-liter car would be more realistic) into a production car — at least for a very wealthy few.
The XL1 is powered by a two-cylinder, 48 horsepower diesel engine and an electric motor drawing on a lithium-ion battery. The battery recharges in about an hour, at the cost of a few cents of electricity. Once the batteries drain, the the diesel engines starts extending its range to more than 300 miles. Another secret lies in the weight of its sleek, aerodynamic shell composed of carbon-fiber, as well as magnesium and aluminum components driving down the weight significantly.
Not that long ago, the XL1 was considered a fanciful concept car, not something that would ever roll down a city street. It’s a sign of how fast materials and hybrid drive-trains are advancing, as well as changing market pressures, that such a vehicle could be built and sold.
For decades, fuel efficiency languished after jumping nearly 70 percent (PDF) following the 1970s energy crises. Then, between 1985 and 2005, there was almost no change. Things are finally moving again. The Obama administration has pushed through a national program in April 2010 to raise new fleet average fuel efficiency to 34 MPG by 2016 and then reach the equivalent of 54.5 miles per gallon by sometime 2017 between 2025..
And if the XL1 hints at what is to come, we may surpass even those goals. Today’s most fuel efficient cars listed by Consumer Reports are the Ford Focus Electric, a combined 107 MPG equivalent, followed by several other models including the popular Toyota Prius hybrid clocking in at about 55 MPG.
While a car as expensive as the XL1 is not likely to make it into many hands — only 250 are slated to be built for now — its design inspiration is expected to make its way into every car the VW Group manufactures by 2020.