Many Americans have already taken action to reduce their energy use and many others would do the same if they could afford to, according to a national survey conducted by Yale and George Mason universities.

Roughly half of the 2,164 American adults surveyed last September and October said they had already taken important steps to make their homes more energy-efficient, and a substantial number - between 10 and 20 percent - said they planned to take action over the next year.

Almost two-thirds of the respondents said that they would like to buy a fuel-efficient car, but over a third said they can't afford one.

"Overall, many Americans are ready, willing and able to save energy at home and on the road. Many others are ready and willing, but need some help," said Anthony Leiserowitz, director of the Yale Project on Climate Change and lead investigator on the survey.

"A national strategy to conserve energy and invest in energy efficiency will find the American people a willing partner."

While saving money is by far the most common reason why people take energy-saving actions - including insulating their attic, caulking and weather-stripping their home, setting their thermostats to more energy-efficient levels and buying a more fuel-efficient car - large numbers of respondents said they were also motivated to reduce global warming, by the desire to act morally, and by taking energy-saving actions that made them feel good about themselves.

By more than a 2-to-1 margin, respondents also said they believe that making changes to reduce their energy use will improve - not diminish - the quality of their lives.

"These data make clear that large numbers of Americans are eager to use less energy and that they have many and varied reasons for doing so," said Edward Maibach, professor and director of George Mason's Center for Climate Change Communication and co-principal investigator on the research.

"We think this survey also lays to rest the notion that Americans feel that saving energy somehow involves sacrifice. Quite the contrary, far more people believe that saving energy will improve the quality of their lives."

The survey also reveals much about the energy-efficiency and energy conservation barriers of greatest concern to large numbers of Americans.

The significant upfront financial costs - simply not being able to afford to take the recommended action - is by far the most pervasive barrier to improving energy efficiency in American homes and cars.

This is especially true for people who currently have completely serviceable, albeit energy-inefficient, home heating and cooling units or cars.

The report concludes that reducing this barrier "may require developing a different financial model (to help people to take these actions); for example, the way mobile phone providers eliminate upfront costs by financing the cost of the phone through the monthly service fees."

The survey, "Saving Energy at Home and on the Road: A Survey of Americans' Energy Saving Behaviors, Intentions, Motivations, and Barriers," was funded by the Yale Center for Environmental Law and Policy, the Surdna Foundation, the 11th Hour Project, and the Pacific Foundation. Respondents to the survey completed two separate questionnaires, two weeks apart, using the nationally representative online panel of Knowledge Networks. The margin of error for the survey was +/- 2 percent.