Americans are more concerned about fuel economy than ever before. And future high mileage technologies look promising. But what's best way to go today if you want to fill up less often- hybrids? Clean diesels? Or just go small? We wondered, too. So we picked six cars with stellar fuel economy ratings to see how they perform when driven to extremes. Welcome to MotorWeek's 2009 power and economy drive.

We prepared our 6 green cars- three full hybrids, two clean turbocharged diesels, and a Smart ForTwo, the highest mileage non-hybrid car you can buy- for a typical weekend family outing: a drive to the mountains.

For the test we partnered with members of editorial staff of Chicago based cars.com. Their presence made sure that the big-city dwellers' perspective was not overlooked.

We also equipped each with a Car Chip Pro data recorder. Car Chip helped us restrain the lead-foots among us, since it sounds an alarm if you're too hard on the gas or brake.

At $22,750, the 2010 Toyota Prius has a combined city-highway government fuel economy rating of 50 miles per gallon, the group's highest.

Road Test Vehicle

2010 Honda Insight » Road Test

The 2010 Honda Insight, at $20,510, is less expensive than Prius. But, at 41 MPG, its combined fuel economy is smaller, too.

The $28,350 2010 Ford Fusion Hybrid, is the first full-hybrid car from a domestic brand. Its combined fuel economy rating is 39 miles per gallon.

The 2009 Volkswagen Jetta TDI clean diesel, our Drivers' Choice Best Of The Year, is a natural for the drive. With a manual transmission and a $22,970 base price, it rates 34 miles per gallon combined.

The 2010 Audi A3 TDI goes on sale soon, with an estimated price of $29,000. It has the same engine as the Jetta TDI, but with an automatic transmission. It too rates 34 MPG combined.

Finally, the 2009 Smart ForTwo coupe with a 36-miles-per-gallon combined rating; we wanted to see how this $12,635 two-seater would perform outside the city environment.

Our three day drive covered over 500 miles- from our studios in Owings Mills, to the Deep Creek Lake region near Cumberland, Maryland. Roads were a good mix of two-lane blacktop, high speed interstate, small town streets, and of course, plenty of mountain switchbacks.

None of them phased the Toyota Prius hybrid. With a total output of 134 horsepower, it seemed up to any challenge.

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2010 Ford Fusion Hybrid » Road Test

PATRICK OLSEN: Toyota is on the third generation of the Prius and I think they nailed it this time—the inside is much more refined and very roomy.

But we were still amazed that the Prius averaged 49.2 miles per gallon. That's very close to the government's rating and the group's best result.

SHAMIT CHOKSEY: They've done a great job with the third-generation Prius. It's almost a premium car now.

KELSEY MAYS: Even though the 2010 Honda Insight hybrid has only 98 horsepower, it too took the higher terrain in stride. Comfort was good, but noise could be lower.

BRIAN ROBINSON: Honda Insight—fun-to-drive little hybrid, economy feel; but it goes along with its economy price.

Insight fuel economy hit 40.5 miles per gallon, again just slightly less than the government rating.

We expected the Ford Fusion Hybrid to be our least fuel-efficient car. But that's because it's every bit a typical mid-size family sedan, with no compromises.

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2009 Volkswagen Jetta TDI » Road Test

If you want the comfort and amenities of a long-distance car, and great mileage, the Ford Fusion Hybrid is the real deal.

And even with a group high 191 horsepower, it still returned 32.9 miles per gallon.

PATRICK OLSEN: What I like about the Ford is it looks like a family sedan, but they need to work on that engine noise. It's really annoying at high speeds.

Now to our diesels. The 2009 Volkswagen Jetta TDI sports 140 horsepower, a manual transmission, and German sport sedan suspension tuning. It was easily the group's favorite car to drive.

SHAMIT CHOKSEY: A great package overall; I mean, that's why we called it our car of the year.

As to VW's claims that a turbo-diesel can match hybrid fuel economy, we'd say that's debatable. At 36.2 miles per gallon, it beat its government rating, but still trailed Prius and Insight.

KELSEY MAYS: The Jetta TDI is a lot of fun to drive, and you don't expect that for a fuel-efficient car.

Road Test Vehicle

2010 Audi A3 2.0 TDI » Road Test

The Audi A3 TDI showed the best combination of driver enjoyment and practicality of our group. With the same 140-horsepower turbodiesel as the Jetta, it too zoomed up the mountains with ease.

BRIAN ROBINSON: Love the small wagon roominess of the A3; fun-to-drive; love the diesel.

PATRICK OLSEN: I enjoyed the ride in the A3 but I found the car overall a little cramped.

A3 TDI fuel economy actually beat Jetta, at 38.2 miles per gallon, due in large part to the S-Tronic Twin-Clutch transmission that, when left in full automatic, shifts faster than the human hand.

Finally, the Smart ForTwo. With only 70 horsepower, we expected the mountains and high speed interstates to take their toll. But they really didn't. The ForTwo managed to keep up very well.

This trip proved to me that the Smart is more than just a city car. It kept up with the group and turned a lot of heads to boot.

Improvements in the Smart's transmission greatly reduced the jerkiness we noted in our original test.

Given how far the Smart was out of its element, 35.3 miles per gallon, again very close to the government rating, is impressive.

Road Test Vehicle

smart fortwo » Road Test

KELSEY MAYS: The ForTwo is easy to park, and it's pretty roomy for its size, but the deal-breaker for me is the fact that, despite its high mileage, it needs premium gas.

While clearly hybrids delivered the best fuel economy in our test, it's clear to us that hybrids, clean diesels, as well as lightweight designs, can all meet the high mileage expectations of consumers when driven sanely.

So it comes down to making compromises regarding driving performance, creature comforts, and just being a hypermiler.

We found each of our six cars to be capable of handling all kinds of routine driving chores. Every one of them, even the Smart, can stand alone as the household's only car. And that to us is very green progress indeed.

Specifications

  • 2010 HONDA INSIGHT: $20,510
  • 2010 TOYOTA PRIUS: $22,750
  • 2010 FORD FUSION HYBRID: $28,350
  • 2009 VOLKSWAGEN JETTA TDI: $22,970
  • 2010 AUDI A3 TDI: $29,000
  • 2009 SMART FORTWO: $12,635