DaimlerChrysler
Diesel-electric Dodge Ram: Pickup gets 15 percent mileage boost.

2008: Dodge Durango SUV with 25 percent mileage improvement.

Ford
Escape Hybrid: SUV rated at 36 in city driving with two-wheel-drive model, nearly double that of the gas-only Escape. Highway driving rated at 31 mpg.
Mercury Mariner SUV: 33 mpg in the city, 29 on the highway.

2007: Mazda Tribute SUV, no mileage data yet.
2008: Ford Fusion and Mercury Milan sedans, no mileage data yet.

General Motors
GMC Sierra/Chevrolet Silverado: 2WD models get 18 mpg city, 21 mpg highway for an increase of 10-12 percent over gasoline siblings.
Saturn Vue: SUV rated at 27 mpg in city and 32 mpg highway — a 20 percent increase over gasoline sibling.

2007: Saturn Aura sedan, no specs available. Chevy Tahoe, GMC Yukon, up to 35 percent mpg boost. Chevrolet Malibu, 15 percent increase.
2008: Chevy Silverado and GMC Sierra pickups that get up to 35 percent mpg increase.

Honda
Insight: two-door rated at 56 mpg on highway and in city but discontinued starting in 2007 model year.
Civic Hybrid: four-door rated at 51 mpg on highway and 49 mpg in city.
Accord Hybrid: rated at 35 mpg on the highway, 29 mpg in the city.

Nissan
Fall 2006: Hybrid version of midsize Altima.

Toyota
Prius: Sedan rated at 60 mph in city, 51 mpg on highway.
Lexus RX 400h: SUV rated at 31 mpg in city driving, two thirds more than its gas-only RX 330 sibling.
Highlander Hybrid: SUV is rated at 32/27 mpg in city/highway driving based on two-wheel-drive model.
Lexus GS 450h: Sports sedan rated at 25 mpg in city and 28 mpg highway, along with 339 horsepower.
Camry Hybrid: Sedan rated at 40 mpg in city, 38 on highway.