Fuel-Sipper Smackdown

Four ultra-fuel efficient cars hit the road to see which one was the best gas value. They all finished strong, but there was one clear winner.

The Challenge

Test drivers at automotive information Web site Edmunds.com wanted to find out what kind of "fuel-efficient car" really got the best mileage.

To find out, they pitted a hybrid, a diesel, a compact and a really tiny mini-compact against one another on a road trip from Los Angeles to Las Vegas.

They put the cars through three real-world driving tests along the way:

1. Back road driving - 334 miles  of 50-65 mile-per-hour driving on  roads through Death Valley

2. City driving - 133 miles of stop-and-go driving in Las Vegas

3. Highway cruising - 209 miles of Interstate at 75 mph

They then combined the results of those tests to determine the overall winner.

The cars they selected were the Ford Focus, the Smart ForTwo, the Toyota Prius (all 2008 models) and a 2005 Volkswagen Jetta TDI. In the end, one car really was the real fuel economy king.

4th place: Ford Focus

Price: $14,395 - $16,925

Avg. mileage: 33.3 mpg

Back roads: 36.9 mpg - 4th place

City: 23.6 mpg - 4th

Highway: 37.5 mpg - 4th

The Ford Focus is a good compact car with good fuel economy, but it was simply outclassed.

An average of 33.3 mpg is commendable, but it's almost 7 mpg less than its closest competitor here, the ultra-small two-seat Smart ForTwo.

The Focus finished fourth in all three segments of Edmunds.com's driving test. It also finished fourth in total fuel costs for the trip.

3rd place: Smart ForTwo

Price: $11,590 - $16,590

Avg. mileage: 40 mpg - 3rd place

Back roads: 43.9 mpg - 3rd

City: 34.0 mpg - 2nd

Highway: 40.0 mpg - 3rd

With its teeny 3-cylinder engine and itty-bitty body, the ultra-mini Smart ForTwo is best suited for city driving. On Las Vegas streets it got 34 mpg, which was still well behind the Prius's unbeatable 52.4 mpg.

But in the other tests that involved high-speed driving, the ForTwo finished third behind the Jetta diesel and the Prius hybrid.

If fuel costs are considered, the ForTwo came in second. The Jetta had better total fuel economy, but diesel fuel is more expensive than even the premium gas required by the ForTwo.

2nd place: 2005 Volkswagen Jetta TDI

Price: (Not current model)

Avg. mileage: 43.81 mpg - 2nd place

Back roads: 47.3 mpg - 1st

City: 32.6 mpg - 3rd

Highway: 48.9 mpg - 1st

VW will bring a new Jetta TDI to the U.S. market this summer. EPA-estimated fuel economy for that car will be 41 mpg on the highway and 30 in the city, thanks to a fuel-efficient diesel engine. The last time VW sold a diesel Jetta here was for the 2006 model year.

Edmunds.com used a 2005 Jetta TDI that was already part of the site's long-term test fleet. EPA-estimated fuel economy for the 2005 Jetta diesel is slightly less than for the 2008 version. Edmunds.com's Jetta finished first in two of the three driving contests, taking the title of "Best Backroads Cruiser" and "Best Highway Flyer."

It finished second to the Prius in terms of total fuel economy but, if you consider fuel costs, it ranked third because of the high price of diesel.

1st place: Toyota Prius

Price: $21,100 - $23,370

Avg. mileage: 47.7 mpg - 1st place

Back roads: 46.0 mpg - 2nd

City: 52.4 mpg - 1st

Highway: 47.7 mpg - 2nd

The Prius was the clear overall victor with the best average fuel economy. While it didn't win every segment of the competition, it at least finished a close second when it missed.

The Prius lagged a bit behind the Jetta in highway and back road driving. In those situations, the Prius's battery-boosted hybrid drive system didn't help much, forcing its small gasoline engine to do most of the work. But the Prius more than made up for it in city driving, which it won by a wide margin.