Forty-eight-point-five miles per gallon.  It's an impressive figure. A little better than the numbers we got in a week of commuting in a Honda Insight last year, in fact.  But this number comes not from a little fuel-sipping hybrid that shuts off at stoplights.  No, this was a pavement-rippling muscle car putting out more than 300 horsepower.

The car in question was the 2011 Ford Mustang V-6.  Ford is marketing the car as the first 300-plus-horsepower V-6, and proof that you don't have to concede to wasting money on fuel and leaving a gigantic carbon footprint behind you in order to own a car you've lusted after.

In an attempt to prove the point, Ford brought a six-speed Mustang V-6, and a team of five drivers to Tennessee's Bristol Motor Speedway.  They aimed to complete 1,000 laps (533 miles) on one tank of gas, but that turned out to be too easy a goal.  The tank finally ran dry after 776.5 miles -- 1,457 laps of the track.

Of course, this doesn't mean you can scrap your plans to buy an Insight and just plan to get 44 mpg out of a pony car going back and forth to the office.  Ford's test was a bit of a publicity stunt, representing conditions even the most dedicated hypermiler could never hope to achieve in the real world.

There is a point, with every car, where aerodynamics and drag, weight and propulsion balance out at near ideal levels, and a car is at its most efficient.  Manufacturers generally aim for a range between 55 and 65 mph for peak efficiency, but the demands of a retro-inspired body lowered that, in the Mustang's case.  The drivers maintained a steady speed of approximately 43.9 mpg on the smooth, traffic-free asphalt.  They kept the engine speed low, the A/C off, and stopped only to change drivers.  In real-world driving, Ford estimates that the V-6 'Stang should manage 19 mpg in the city and 31 on the highway.

So the real story here is not that a muscle car managed almost Prius-like mileage.  That was just a stunt, and a V-6-powered Camaro could likely put up similar numbers.  No, the real story is that Ford is marketing the Mustang on fuel economy.  If you've ever needed proof that we were moving toward a day when all cars were green cars, just look at that -- even the engineers behind classic nameplates associated with monstrous V-8 power and a devil-may-care attitude toward environmental responsibility now find it necessary to stage publicity stunts to burnish their green credentials.