In an effort to reduce air emissions from mobile sources, the EPA instituted reformulated gasoline (RFG) regulations. EPA's reformulated gasoline (RFG) rules, required oxygenates (e.g., MTBE, ethanol), reduced vapor pressure (Reid Vapor Pressure or RVP reduction) and reduced toxics. However, there were unintended problems with oxygenates and in May 2006, the EPA reversed the RFG rule's requirement for oxygenates by eliminating the requirement. While RFG continues in its modified form with some benefits to the environment, it is clearly not sufficient. So, it is time for us to put our "government regulator" hats on and decide what we would advocate as next steps. Some of the best opportunities are available to us by not only changing fuels but also the vehicles that run on those fuels. The following are some examples of vehicle/fuel combination possibilities:

• traditional vehicle/gasoline (with or without a bit of ethanol)
• diesel vehicle/ clean diesel (with or without added biodiesel)
• hybrid (newer plug-ins or traditional hybrid)/gasoline and electric power mix
• fuel cell/ hydrogen
• flex-fuel vehicle/ E-85 gasoline
• natural gas vehicle/natural gas

Once you review the above material, write a 3 (maximum) page paper that includes the following:

Select ONE of the above vehicle/fuel combinations that you believe offers us hear in the U.S , the most environmental advantages AND the least economic and practical hurdles to implementation. You may draw comparisons to the other vehicle/fuel choices, but try and focus on your selection in your discussion.

Explain the environmental advantages, steps to implementation and solutions to problems in implementation. When you consider environmental advantages (and disadvantages), keep in mind that these may include more than air emissions from the tail-pipe. For example, a plug-in electric car may operate without tail-pipe emissions (a plus), but the electricity could be made from coal (a negative), as coal does generate air emissions. (Ah, life is never simple, is it?). In your answers, try and include as much of the entire environmental impact of the vehicle as possible - from manufacture through end use. Also, feel free to consider economics and geopolitical factors as environmental issues as these also tie into environmental health.

There is no right or wrong answer here. What we project this year may, in fact, turn out to be the wrong answer as technological developments occur or fuel availability changes. The important thing is to provide a good basis for your choice and arguments.