WASHINGTON — When it comes to saving energy, people in the United States know that driving a fuel-efficient car accomplishes more than turning off the lights at home.

But that doesn’t mean they’ll do it.

A new poll shows that while most of those questioned understand effective ways to save energy, they have a hard time adopting them.

Six in 10 surveyed say driving a more fuel-efficient car would save a large amount of energy, but only 1 in 4 says that’s easy to do, according to the poll by the AP-NORC Center for Public Affairs Research. People also are skeptical of carpooling or installing better home insulation, rating them as effective but impractical.

On the other end of spectrum, 8 in 10 say they easily can turn off the lights when they leave a room, and 6 in 10 have no problem turning up the thermostat in summer or down in winter, although fewer than half think those easy steps save large amounts of energy.

Even those who support conservation don’t always practice it.

Cindy Shriner, a retired teacher from Lafayette, Ind., buys energy-efficient light bulbs and her 2009 Subaru Impreza gets nearly 30 miles per gallon on the highway.

Still, she keeps her house at about 73 degrees year-round, despite government recommendations to turn thermostats to 68 degrees in winter and 78 degrees in summer.

“I’m terrible,” Shriner, 60, said in an interview. “In all honesty we have extreme weather in all seasons” in Indiana, she said, and her thermostat settings keep her comfortable.

Her parents recently qualified for a grant under the economic stimulus law that paid for a new furnace and insulation, Shriner said. She said such programs are important to improve energy conservation.

The public looks to large institutions for leadership in saving energy, believing that individuals alone can’t make much of a difference. Nearly two-thirds look to the energy industry to show the way toward energy conservation, and nearly 6 in 10 say the government should play a leading role. Democrats, college graduates and people under 50 are the most likely to hold industry is responsible for increasing energy savings.

The poll, paid for by a grant to the AP-NORC Center from the Joyce Foundation, shows that just 4 in 10 questioned think their own actions can significantly affect the country’s energy problems. Some 15 percent say individual actions make “a very large difference,” while 7 percent say individual action makes no difference at all.

On some energy topics, people are in the dark.

Only 1 in 3 reports knowing a lot or a great deal about the government’s Energy Star product labels, which are meant to help consumers choose energy-efficient appliances and other products. Even fewer, 25 percent, report detailed knowledge about fuel-efficiency standards for cars. Not even 20 percent know a lot or a great deal about rebates for energy-saving products, home renovation tax credits or home energy audits.

About 6 in 10 people cite lack of knowledge about energy-saving products as a major reason they don’t do more to conserve.

Jennifer Celestino, 29, of Buffalo, N.Y., said she might do more if she knew how much energy she was using compared with her neighbors.

“If you had information that says, ‘Hey, your household uses more than the typical house in your ZIP code,’ that would get my attention,” said Celestino, a workforce analyst at an insurance company.

Lacking hard data, nearly half of those questioned say they use somewhat or a lot less energy than others in their community, while only 9 percent think their consumption is above average.

Overall energy use by people in the United States is four times the world average, according to the Energy Information Administration, but Americans use less energy per person than people in countries such as Canada, Norway and Iceland. Average energy use by Americans declined by about 9 percent from 2005 to 2009, largely because of increased efficiency of appliances and machinery, and the economic downturn, the EIA said.

Dori Spaulding, a stay-at-home mom from Niceville, Fla., worries about high energy bills, particularly in the summer, but says her hometown “is a hot place and we have small kids.” Her home windows are not as efficient as they should be, Spaulding said, but they aren’t broken and “I don’t have 10 grand to replace the windows.”

Spaulding, 33, said she and her husband, an Air Force pilot, have considered buying a hybrid or electric car. But for now they drive a minivan and station wagon. She said she needs the room for her two children and the triathlon club she leads, but acknowledged that the vehicles fit her lifestyle.

“I think that Americans want what we want, and we want it now,” she said.

The survey was conducted from March 29 to April 25. It involved landline and cellphone interviews with 1,008 adults nationwide and has a margin of error of plus or minus 3.1 percentage points.