Not a concept car or prototype, my XL1 is actually a limited edition production car, one of just 200 examples built and sold by VW worldwide in 2014-15 (26 cars were sold to UK nutters like me!). It’s officially the world’s most aerodynamic and most fuel-efficient production car.
I purchased mine new in July 2015 – it’s in regular use in all weathers and I’ve so far driven 7000 miles. It does 313 miles per gallon!! Well, that’s the official government-tested figure anyway. The fuel tank holds just ten litres of diesel, but I get over 300 miles on a tank no matter how I drive it. The most fun car I’ve ever owned, I could never part with it!
In case you want to get into the detail: The main purpose of Volkswagen’s XL1 project was to develop new technology and solutions that will enable mainstream VW cars to be more fuel-efficient. It took 12 years to develop at a cost of over £1 billion – a similar R&D budget to the Bugatti Veyron.
It’s an electric-diesel hybrid with a carbon fibre chassis, body panels and seats. magnesium gearbox casing and wheels, and ceramic brakes. Weighs just 795 Kg. The XL1 has unlimited range and achieves its fuel economy of 313 mpg (0.9 litres/100 km) with emissions of just 21 g/km of CO2. Even using diesel alone, it’s capable of 160 mpg! It’s powered by an 830 cc two-cylinder turbo diesel engine with 47 bhp, and a 27 bhp electric motor, delivering power to the rear wheels through a 7-speed dual-clutch gearbox (DSG). The drag coefficient is incredibly low at just 0.189. Every component of this car has been designed to be as light as possible and/or to reduce rolling resistance or air drag. And yet the car’s well-appointed with air-con, hi-fi, Bluetooth music/phone connection, sat-nav, cruise control, computer, park sensors, powerful LED headlamps, etc.
The passenger seat is located further back than the driver’s, to free up elbow space and allow the car to be narrower and thus more aerodynamic to save more fuel. The XL1 is shorter and narrower than a Volkswagen Polo, but lower than a Porsche Boxster. There are no rearview mirrors – thus greatly reducing air drag and to save more fuel. Instead, two small door-mounted cameras feed pictures to internal TV screens.
Steering is incredibly direct and precise as there is no power-assistance (it’s not needed as the car is so light). Butterfly doors enable easy access even though the car is so low. The lithium-ion battery (capacity: 5.5 kWh) which is integrated into the front section supplies the E-motor with energy and is constantly being recharged when the car is going downhill or braking or when the diesel engine is running. The engine cuts in and out automatically whenever it is needed.