Un poco de invertigación en Internet.
El único detalle es que son resultados con carros que vender en USA:
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Top 10 Fuel-Saving Cars
With the cost of fuel rising to levels the rest of the world endures as a matter of course, North Americans are beginning to consider gas mileage when purchasing a car. So we've created a list of the 10 best fuel-sippers... but with a difference. Since the most economical cars don't always fit everyone's needs we've chosen 10 automobiles that combine fuel saving with what consumers really want in a car. Note: Automatics will use slightly more fuel than manuals.
1) Toyota Prius
A hybrid gas-electric, the Prius wins for the way its second-generation technology has been presented in an attractive hatch/sedan envelope that delivers big in comfort and convenience. Yes, it actually gets better mileage in city driving: 60 mpg City, 51 mpg Highway (automatic)
2) Honda Civic Hybrid
Obviously the hybrids take first in class but Honda has chosen to offer its advanced technology in a well-known and respected family sedan, rather than create a purpose-built vehicle like the Prius. All-new for 2006, the Civic offers refinement like you've not yet seen in a Civic. New looks, more room... If you like the Civic, you'll like the Hybrid even more: 50 mpg on city and highway (CVT).
3) Volkswagen Golf TDI, aka New Beetle TDI, aka Jetta TDI
We've combined these three diesels because they're built on the same platform and use the same advanced technology. Diesel proponents claim to nearly equal hybrid mileage figures without complex and potentially costly battery/electronic systems: 36 mpg City, 47 mpg Highway (manual)
4) Mini Cooper
As proof that you can still have fun while saving on fuel, the Mini Cooper stands alone. Corners like a go-kart, holds four people and a little luggage, perfect for the city, no slouch on the expressway: 28 mpg City, 37 mpg Highway (manual)
5) Hyundai Elantra
Compact on the outside yet listed by the EPA as a midsize car because of a spacious interior. 4-cylinder engine is big on power while sipping fuel. Plus it offers a powertrain warranty that protects the buyer for ten years: 27 mpg City, 34 mpg Highway (manual). Oh, you can get the Elantra as a hatchback, too (which makes it even cooler in our books.
6) Ford Focus Station Wagon
Any of the Focus lineup could make this list now that the car has overcome its quality problems. But the wagon is versatile while retaining the edge in handling that makes it a delight to drive. A recently new engine makes it even better: 27 mpg City, 35 mpg Highway (manual)
7) Honda Accord 4-Cylinder
Easy to recommend as a great family car, but what you may not realise is that the Accord's 4-cylinder engine has all the power most families need, unless they're towing Airstream trailers: 26 mpg City, 34 mpg Highway (manual)

Nissan Altima
Nissan has proven that style need not be ignored when buying a family car, for the Altima is both beautiful and practical. But forget the V-6 and opt for the 4-cylinder engine. Torque is what matters and the 4-cylinder Altima has plenty: 23 mpg City, 30 mpg Highway (manual)
9) Chevrolet Malibu MAXX
A real winner in our book for providing a spacious, versatile interior within an intelligently-sized exterior that looks bigger than it really is. The V-6 engine is powerful and powers past the gas pumps, too: 22 mpg City, 30 mpg Highway (automatic)
10) Buick Lucerne
You need to stick with the V-6 if you want better gas mileage (there's a V-8 available) but you'll be rewarded with a big car that returns 19 city, 28 highway. From an automatic, no less.