Don't bother buying the more expensive high-octane fuel unless your owner's manual specifically recommends it. If your vehicle was made to run on 87 octane and you chose 92 octane, there will be no improvement to your engine power, fuel efficiency, speed, or performance. The price difference per fill-up, however, amounts to an extra gallon of gasoline. If all drivers used lower-grade octane, $3 billion per year would be saved - enough to buy more than 107,000 hybrid cars. 

If your vehicle has a diesel engine, consider using biodiesel. Not only is biodiesel more energy efficient than other fuels, it's renewable, biodegradable, and free of the sulfur pollutants characteristic of traditional petrodiesel. If you were to begin using biodiesel B20 (a fuel containing 20% biodiesel) intead of conventional diesel, you would conserve an average of 50 gallons of petroleum per year and reduce your carbon emissions by 30%. If all diesel cars sold this year used B20 fuel, the annual savings would equal 23.8 million gallons of petrodiesel -- enough to transport more than nine hundred thousand children to school and back for an entire year.

Choose recylced fabrics for couches, drapes, chairs, and other upholstery. If half of the polyester fabric made in the US each year were produced with recycled materials, it would be enough to cover the entire state of New York.

Limit vegetation removal during your home's construction to help prevent erosion. Erosion is a leading source of pollution to America's rivers, lakes, and streams because home drainage and storm water runoff contain harmful chemicals.

Buy them and save water. They come with two flush options: The first uses 0.8 gallons of water, the second uses 1.6 gallons (to dispose more waste). This can reduce water usage by up 67% compared with the traditional toilet, which uses about 3 gallons in a single flush. If every household had a dual-flush toilet, the total savings from a single flush per home would equal the amount of water flushed in stadium bathrooms throughout the entire baseball season.

Try to find drywall made with at least 75% recycled content, including 10% or greater postconsumer content. You may also consider drywall produced with synthetic gypsum or fly ash instead of natural gypsum. In both cases, you'll help save energy, reduce waste, and reduce the habitat disruption associated with gypsum mining. If just 1% of all drywall used for US construction each year had at least 75% recycled content, the total materials saved could build a sheet of drywall nearly eleven feet high and as long as the Great Wall of China.

You can create an imporved envelope of insulation around your home by building with materials to reduce drafts and by sealing cracks and gaps that permit air and moisture exchanges. This could reduce your heating and cooling costs by about 2,250 kilowatt-hours of energy and $180 per year. If every new home were built with a tightly insulated envelope, the energy savings would equate to more than doubling the fuel efficiency of the 210,000 postal vehicles that deliver the US mail.

Install a programmable thermostat for your heating and cooling system. A programmable thermostat can save you about $100 every year in energy costs. If just one in ten households did this, we'd prevent seventeen billion pounds of greenhouse gases from being let loose, or about as much gas as all the cows in the US burp per day! Cows burp methane, a greenhouse gas.