Ellington

Toyota Prius
• Type of car: Hybrid
• Body type: Sedan
• How it works: Energy is captured whenever the car brakes, stored in the batteries and used whenever possible instead of fuel.
• Estimated cost: $22,000
• Combined MPG: 46 mpg
• Type of energy: Gasoline at gas station
• Other models: Ford Escape ($29,300; 32 mpg), Honda Civic Hybrid ($22,600; 42 mpg)

Volkswagen Jetta TDI
• Type of car: Diesel/Biodiesel
• Body type: Sedan
• How it works: Converts vegetable oil or animal fats into a chemical to be used as energy for biodiesel or simply diesel can be used.
• Estimated cost: $21,900
• Combined MPG: 35 mpg
• Type of energy: Diesel or Biodiesel (converting vegetable oil or animal fats)
• Other models: Jeep Grand Cherokee CRD ($34,400; 22 mpg), BMW X5 Diesel ($45,900; 22 mpg)

Chevy Impala E85
• Type of car: Ethanol
• Body type: Sedan
• How it works: This flex-fuel capability has Ethanol compatibility for virtually all the car's components or can run on gasoline.
• Estimated cost: $22,400
• Combined MPG: 22 mpg
• Type of energy: Gasoline at Gas Stations or Ethanol from fast-food restaurants
• Other models: Chrysler Sebring E85 ($29,300; 21 mpg), Chevrolet Silverado E85 ($29,400; 18 mpg)

VentureOne
• Type of car: Plug-in Hybrid
• Body type: Coupe
• How it works: This type of car travels up to 40 miles on electricity and then converts to gasoline.
• Estimated cost: $18,000
• Combined MPG:100+ (40 miles on all-electric mode)
• Type of energy: Electricity from your house and gasoline at gas stations
• Other models: Plug-in hybrids are not yet available for the individual consumer

Chevrolet Volt
• Type of car: Electric
• Body type: Sedan
• How it works: An electric car is powered by an electric motor instead of a gasoline engine.
• Estimated cost: The demand is pushing the price up between $30,000-$40,000
• Combined MPG: 150+ mpg (40 mpg are entirely electric)
• Type of energy: Charging the battery and gasoline at gas stations
• Other models: Projected to release in 2011

Smart ForTwo
• Type of car: Gasoline
• Body type: Small Car
• How it works: Operating like a traditional car, the smart car is eco-friendly because of its size.
• Estimated cost: $15,000
• Combined MPG: 36 mpg
• Type of energy: Gasoline at gas stations
• Other models: Mini Cooper ($18,700; 35 mpg), Toyota Yaris ($12,400; 32 mpg)