Fuel efficient cars are able to get a higher amount of miles to the gallon. Fuel consumption can be affected by many factors such as newness of the engine, type of fuel, type of vehicle and the condition of the car.http://www.fueleconomy.gov/feg/why_differ.shtml Also, miles per gallon change depending on whether you are driving on the highway or in the city.http://www.fueleconomy.gov/feg/why_differ.shtml

Choosing a car with the best fuel economy can save over $1000 at the fuel pump.http://www.fueleconomy.gov/feg/why.shtml Some vehicles that use alternative fuels are eligible for tax credits, which provide additional savings.http://www.fueleconomy.gov/feg/why.shtml Fuel efficient cars make the country as a whole less dependent on foreign oil, a nonrenewable fuel that will be used up eventually.http://www.fueleconomy.gov/feg/why.shtml Many alternative fuels produce a smaller amount of carbon dioxide.http://www.fueleconomy.gov/feg/why.shtml Some alternatives like electric cars do not release carbon dioxide at all.http://www.afdc.energy.gov/afdc/vehicles/electric_what_is.html

Hybrid-electric vehicles (HEV) are a mix between the conventional gasoline engine and an electric motor.http://www.fueleconomy.gov/feg/hybridtech.shtml In the future, there may be electric hybrids that use alternatives like hydrogen fuel cells instead of gasoline.http://www.afdc.energy.gov/afdc/vehicles/hybrid_electric.html Hybrids benefit consumers because they can get 40 to 70 miles per gallon.http://www.afdc.energy.gov/afdc/vehicles/hybrid_electric_benefits.html Plus, they have lower carbon dioxide emission rates than automobiles that run on gasoline alone.http://www.afdc.energy.gov/afdc/vehicles/hybrid_electric_benefits.html

Availability: Unlike some other alternative vehicles, there are many hybrid cars, trucks and buses on the market today.http://www.afdc.energy.gov/afdc/vehicles/hybrid_electric_availability.html

Electric vehicles (EV) have electric motors that use rechargeable batteries.http://www.fueleconomy.gov/feg/evtech.shtml The car can be charged using a power source located outside the car or one housed inside the vehicle.http://www.afdc.energy.gov/afdc/vehicles/electric_what_is.html EVs do not produce any exhaust from the tailpipe, which lessens the total amount of pollutants released each year by vehicles.http://www.afdc.energy.gov/afdc/vehicles/electric_what_is.html They are also quieter than cars with a gasoline engine.http://www.fueleconomy.gov/feg/evtech.shtml EVs have greater energy efficiency because they change 75% of their energy into power for car operations.http://www.fueleconomy.gov/feg/evtech.shtml

On the negative side, batteries can be pricey and heavy.http://www.fueleconomy.gov/feg/evtech.shtml It can take up to 8 hours to recharge a battery, and the average EV can only go up to 200 miles before needing a recharge.http://www.fueleconomy.gov/feg/evtech.shtml Because of these issues, it is common to only use EVs for short commutes and car services that do not go a long distance.http://www.afdc.energy.gov/afdc/vehicles/electric_what_is.html

Availability: Some manufacturers that offer all electric cars are Tesla, Ford and Chrysler.http://www.afdc.energy.gov/afdc/vehicles/electric_availability.html

Fuel Cell Vehicles (FCV) operate by converting hydrogen gas into electricity. This energy fuels the electric motor.http://www.fueleconomy.gov/feg/fuelcell.shtml The hydrogen gas is stored in a fuel cell. FCVs also have a high-output battery that gives extra power to the motor.http://www.fueleconomy.gov/feg/fuelcell.shtml

FCVs release plain water instead of pollutants.http://www.fueleconomy.gov/feg/fcv_benefits.shtml As a result of using hydrogen cars, a smaller amount of greenhouse gases and smog will be in the air. These cars also convert more energy than alternatives that use gasoline.http://www.fueleconomy.gov/feg/fcv_benefits.shtml

However, there are some obstacles for FCVs to overcome before they are widely accepted in the car market. The cars themselves are expensive to make.http://www.fueleconomy.gov/feg/fcv_challenges.shtml Therefore, the cost of the car is unattractive to consumers.http://www.fueleconomy.gov/feg/fcv_challenges.shtml Currently, there is not a mass produced method to offer hydrogen to the public.http://www.fueleconomy.gov/feg/fcv_challenges.shtml Also, fuel cells are heavier and less durable than their counterparts.http://www.fueleconomy.gov/feg/fcv_challenges.shtml

Availability: There are no hydrogen cars on the market. However, there are some buses in production.http://www.afdc.energy.gov/afdc/vehicles/fuel_cell_availability.html