Here’s some scary news: It takes only one pint of oil to produce a one-acre slick on surface water.

To dispose of used motor oil safely, carefully pour the oil into a suitable container. You can buy specially designed one at an automotive store or just use a clean, preferably clear, container with a closeable lid. (Don’t use containers that previously contained household chemicals such as bleach.) Plastic milk jugs with screw caps work well.

The Granite State Clean Cars Program (http://des.nh.gov/organization/divisions/air/tsb/tps/gsccp/) lets participating dealers put a special label in the window of new vehicles that meet environmentally superior performance ratings.

• Park in the shade in summer to keep your car cool and minimize evaporation of fuel.
• If you have a garage, use it as much as possible to keep your car warm in winter and cool in summer.
• If you have to park outdoors, windshield shades can cut down on summer heat and help keep the frost off in the winter.

• Use regular gasoline unless your owner’s manual says otherwise. Unless your car requires premium, high-octane fuels improve neither fuel economy nor performance and will just waste your money.
• Don’t overfill the tank or try to top it off beyond where the automatic nozzle clicks off. Spilled gas evaporates to aggravate smog formation and can leak into groundwater.

Here are some tips we've come across. Feel free to add your own:

• Keep your tires properly inflated. Tires should be inflated to the pressure recommended for your vehicle; usually you can find this number inside the door frame or in your owner’s manual. For every three pounds below recommended pressure, fuel economy goes down by about 1 percent. Tires can lose a pound of pressure a month, so check pressure regularly, and especially before going on a long trip or carrying heavy loads. Also: Don’t buy “aggressive” tread tires if you don’t need them.