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No, judged against vehicles that are purpose-designed to be green, there's nothing particularly eco-friendly nor fuel-sipping about a V-8 engine.

However, given the luxury and the freedom of choice, some people simply want one. Some may even need one, and if that's the case then you may still be interesting in maximizing your MPG--which is where the following five vehicles come in.

We've picked the sports car, truck, SUV, sedan and pony car with the highest MPG, to see which really are the greenest V-8s on sale...

2012 Mercedes-Benz SLK55 AMG

At 22 MPG combined, the SLK55 is actually the V-8 with the best fuel consumption on sale. That may be a little like saying "least irritating Justin Bieber song", but if you like V-8s (or Karma-owning Justin Bieber) then you take what you can get.

The SLK55 even manages a semi-respectable 28 MPG on the highway, no doubt thanks to its 7-speed automatic gearbox that drops the revs to particularly low levels, and huge torque that means the SLK rarely needs much throttle to move around. If you want a V8 sports car but don't want the fuel bills, the SLK55 could be the car for you.

2012 Cadillac Escalade Hybrid 2WD

Is this the first Escalade we've featured on GreenCarReports? It's something of an antichrist in the world of green vehicles, as one of the ultimate statements of bold, brash, "screw-you, planet" wealth, following Hummer's demise.

However, the Escalade Hybrid 2WD is actually (whisper it) the most efficient V8 on sale, in city driving at least. At 20 MPG, it matches GM's other hybrid trucks and SUVs, knocking all others in the class into second place. Want to low-carbon your next rap video? You know what you have to do.

2012 Chevrolet Silverado 1500 Hybrid 2WD

With the same 6.0-liter V-8, hybrid system and variable automatic transmission, it's no surprise that one of GM's trucks takes the top slot for most efficient V-8. It manages 20 MPG in the city, 23 highway and 21 combined.

That makes it one of the most efficient trucks out there if you need a V-8, and as a gasoline-powered vehicle it'll be significantly cleaner than its diesel-engined equivalent. If you need to haul stuff, then a hybrid pickup truck is the way to go.

2012 Audi A8

Want to cruise in style? There are few better large luxury sedans than the Audi A8, which is convenient since it's also the most efficient. It uses a 4.2-liter V8 to reach as much as 28 MPG on the highway, also doing 18 MPG city and 21 MPG combined.

You can thank cylinder-deactivation technology for the surprising highway economy. By shutting down half of the A8's V-8 on low throttle loads when cruising, fuel consumption is cut dramatically. Ticking the throttle a little harder will bring back the full force of that engine. You will need to fill it up with premium gasoline so fuel costs will hardly be low, but when you're spending $80,000 on a luxury car, a tank of fuel is mere pocket change.

2012 Ford Mustang

"Five-point-oh" doesn't usually scream economy to people, but surprisingly the Ford Mustang, with its 5.0-liter V-8, has the best fuel consumption of the pony cars. It'll do 20 MPG combined whether auto or manual, the automatic being better in the city at 18 MPG versus 17 MPG, and the manual taking the highway crown at 26 MPG, versus 25.

Sure, nobody really buys a V-8 Mustang for economy (that's what the cheaper V-6 is for, really) but it still sees off its Dodge Challenger and Chevrolet Camaro rivals (both 19 MPG combined), so it'll get you a little further on that V-8-fuelled road trip.

If you've made it this far, we thank you. Normal service will be resumed soon...


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