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Climate Change Contacts

Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Climate Change in the Pacific Southwest
— Transportation

Fuel Efficient Vehicles and Alternative Fuels Smart Choice Guide:
Alternative Fuel Selection

Smart Choice Fact

Alternative fuels are derived from resources other than petroleum. Some are produced domestically, reducing our dependence on imported oil, and some are derived from renewable sources. Often, they produce less pollution than gasoline or diesel.

EPA, under the Energy Independence and Security Act of 2007, is responsible for revising and implementing regulations to ensure that gasoline sold in the United States contains a minimum volume of renewable fuel. The Renewable Fuel Standard program will increase the volume of renewable fuel required to be blended into gasoline from 9 billion gallons in 2008 to 36 billion gallons by 2022. The new RFS program regulations are being developed in collaboration with refiners, renewable fuel producers, and many other stakeholders. Visit the Renewable Fuel Standard Program for the most updated information on the proposed rulemaking, including fact sheets on EPA’s lifecycle analysis of GHG emissions for renewable fuels.

Cleaner Fuels: Alternative Fuel Options provides links to EPA and non-EPA Web-based resources that provide additional information on transportation and fuels. Links go directly to specific Web sites or documents that address fuel-related trends and issues.

  1. U.S. Environmental Protection Agency Resources
  2. Other Federal Departments & Agencies
  3. State, Local, and Regional Programs
  4. Non-Governmental Organizations

Consumers have more choices now than ever before when it comes to clean and efficient vehicles. Although gasoline still dominates, new hybrid technologies, alternative fuel vehicles and advanced emission control systems allow the cars we drive today to be significantly cleaner. Even among the cleanest technologies, however, environmental impact, fuel efficiency, cost, benefits and availability can really vary.  To learn about the availability, cost, fueling options, benefits, and safety of each of the alternative fuels, please see tabs below.  Contact Grace Change (cheng.grace@epa.gov) for more information.

Hybrid Electric

Hybrid electric vehicles commercially available today combine an internal combustion engine with a battery and electric motor.  For more information, please visit the following links:

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Compressed Natural Gas (CNG)

Smart Choice Fact

Natural Gas reduces 60-90% smog-producing pollutants, and lowers 30-40% greenhouse gas emissions.

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Natural gas can be used in all classes of vehicles - motorcycles, cars, vans, trucks, buses, lift trucks, locomotives, even ships and ferries. Natural gas can be used either by converting an existing gasoline or diesel engine, or by using a purpose built natural gas engine.  For more information, please visit the following links:

Ethanol (E85)

Smart Choice Fact

Flex Vehicles operating on E85 usually experience a 20-30% drop in miles per gallon due to ethanol’s lower energy content.

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Ethanol is mostly used in flexible fuel vehicles, which are capable of operating on gasoline, E85 (85% ethanol, 15% gasoline), or a mixture of both.



Smart Choice Fact

Diesel vehicles are 30-35% more fuel efficient than gasoline.  Ultra Low Sulfur Diesel is a cleaner-burning diesel fuel that contains 97% less sulfur than low-sulfur diesel (LSD).

Diesel vehicles may be making a comeback. Diesel engines are more powerful and fuel-efficient than similar-sized gasoline engines (about 30-35% more fuel efficient). Plus, today's diesel vehicles are much improved over diesels of the past.

Plug-In Hybrid

Plug-in hybrid electric vehicles (PHEVs) combine the benefits of pure electric vehicles and hybrid electric vehicles. Like electric vehicles, they plug into the electric grid and can be powered by the stored electricity alone. Like hybrid electric vehicles, they have engines that enable greater driving range and battery recharging.

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Hydrogen Fuel Cell

Smart Choice Fact

Hydrogen produces no air pollutants or greenhouse gases when used in fuel cells.

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Hydrogen fuel cell vehicles are zero emission and run on compressed hydrogen fed into a fuel cell “stack” that produces electricity to power the vehicle.

Hydrogen Internal Combustion Engine (ICE)

A hydrogen internal combustion engine (ICE) vehicle uses a traditional ICE that has been modified to use hydrogen fuel. The U.S. Department of Energy's FreedomCAR and Vehicle Technologies Program have identified hydrogen-powered ICE vehicles as an important mid-term technology on the path to the hydrogen economy.

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Propane, also known as liquefied petroleum gas (LPG), is used by many fleets. It has a high energy density, giving propane vehicles good driving range, and propane fueling infrastructure is widespread.

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Smart Choice Fact

Biodiesel should be domestically produced from non-petroluem, renewable resources

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Biofuels are those made from feedstocks that have taken their carbon content from the atmosphere relatively recently (i.e., in the last few decades). By contrast, fossil fuels are made from carbon fixed from the biosphere millions of years ago. This difference has implications for the global-warming potential of the fuel, as the carbon emitted by biofuels is recycled from the atmosphere while fossil fuels dump excess carbon into the atmosphere.

Alternative Fueling Stations

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