One of the best ways to make a very fast car is to start with a small vehicle that's extremely light and strong, and add a more powerful engine.

That's the genesis of the Volkswagen XL Sport unveiled yesterday at the Paris Motor Show.

If the small, lightweight vehicle happens to be the ultra-economical Volkswagen XL1 diesel plug-in hybrid, with a carbon-fiber reinforced plastic bodyshell, just think what adding more power could do.

Volkswagen XL1 (European model), New York City, Dec 2013

Volkswagen XL1 (European model), New York City, Dec 2013

The XL1, with only 250 produced and sold--each at a cost well over $100,000--is the most economical vehicle in the Volkswagen lineup. The XL Sport, if it were to go into production, would not be.

DON'T MISS: Volkswagen XL1 138-MPG Diesel Plug-In Hybrid: Drive Report

The recipe for the XL Sport runs roughly as follows:

  • Take one Volkswagen XL1
  • Remove the two-cylinder diesel engine, the electric motor, the battery pack, and the power electronics
  • Add one 197-horsepower V-twin engine from a Ducati 1199 Superleggera motorcycle
  • Fit racing suspension under considerably wider bodywork
  • Test

The result, according to VW, is a 1,962-pound car with minimal frontal area and a drag coefficient of 0.258 that can achieve 168 miles per hour on less than 200 horsepower.

Volkswagen XL Sport concept

Volkswagen XL Sport concept

The Ducati motorcycle brand is now owned by the VW Group, and this project is a mix of technologies from two very different parts of the sprawling global automaker's portfolio.

The 1.2-liter V-twin engine is about as advanced as any motorcycle engine can get, with titanium connecting rods, other components of magnesium alloy, and Ducati's renowned desmodromic valve gear.

It powers the rear wheels through VW's seven-speed direct-shift gearbox, and can rev to 11,000 rpm. The company calls it the most powerful two-cylinder engine in the world.

VW quotes acceleration time from 0 to 62 mph of 5.7 seconds.

Volkswagen XL Sport concept

Volkswagen XL Sport concept

That's hardly supercar timing--there's a model of the new Chevrolet Corvette that does 0 to 60 mph in less than 3 seconds--but it's the top speed that's the impressive part of the XL Sport.

ALSO SEE: Ultra-Efficient VW XL1: Now An Urban Legend, Debunked By Snopes

To achieve it, the designers stayed with the slim passenger compartment of the two-seat XL1, which staggers its seats to reduce cabin width. The driver is slightly ahead of the passenger, whose legs and feet sit alongside the driver.

But while the XL1 echoes the aerodynamic teardrop shape, with a narrower back end than front, the XL Sport is as wide at the rear as it is up front.

Volkswagen XL Sport concept, 2014 Paris Auto Show

Volkswagen XL Sport concept, 2014 Paris Auto Show

That's to accommodate very wide tires, of course, part of an entirely re-engineered chassis and suspension system optimized for high performance rather than fuel efficiency.

The base XL body, with its wider back end, received an enormous amount of aerodynamic work to ensure proper cooling and enough downforce that it wouldn't turn into a wing and lift off at the highest speeds.

Frontal air vanes, vents in the wheel arches, ducts in the hood to let air escape, and a Lamborghini-derived extending rear spoiler are all new to the XL.

MORE: Orders For 261-MPG Volkswagen XL1 Exceed Production of 200

Presently the XL Sport is just a concept car--but, remember, that's how the Volkswagen XL1 began too.

The total production of all 250 XL1s has now been sold, by the way.

For all the news about concepts and new production cars, see our Paris Motor Show news page.

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