Go Green Tip of the week: 4/27/08

Make sure to replace dirty air filters and get regular oil changes with the recommended grade of oil (be sure the old oil is recycled!). You could improve fuel economy 10% or more.

Extra-important when planning a vacation: Carrying around an extra 100 pounds reduces fuel economy by about 1-2% The reduction is based on the percentage of extra weight relative to the vehicle's weight and affects smaller vehicles more than larger ones.

Park in a garage or in the shade to keep your car cool in the summer. Use a windshield shade if parking outdoors Physics lesson: As the temperature rises, gasoline expands, meaning you get less energy per gallon, and therefore fewer miles per gallon. A cool car will help you get the most out of a tank. Plus, when you suit down in a cool car, you're less apt to crank the air conditioner, which can reduce fuel economy as much as 12%.

According to some estimates, a surprising 10-17% of cars on the road have broken or missing gas caps. A new one usually costs about $15. A faulty gas cap allows gas to evaporate, which not only means you're buying gas that you won't use, but also contributes to air pollution, particularly smog. One study in Kansas found a leaky gas cap can be responsible for 175 pounds of air pollution (not counting carbon) in a year. That means more smog, which triggers asthma attacks.

Keeping tires properly inflated can improve fuel efficiency by 3% or more. An estimated one in four vehicles has tires that are out of alignment. Tires out of alignment can reduce fuel economy by as much as 10%.

Check your own fuel economy when you fill up. Use a little notebook: divide miles driven since last fuel-up by gallons pumped. If you see it slipping, you can identify problems early. If you make the same commute each day, but get better gas mileage one week over the next, it means you're burning more gas to drive the same route. That's means more oil pumped, refined and burned, producing pollution at each step of the way. At the gas station, divide miles driven/by gallons pumped for MPG.

Follow the speed limit. A rule of thumb is every 5 mph costs your fuel economy about 7%. Avoid "jack rabbit" starts, aggressive driving and tire-squealing stops. Gas mileage usually decreases rapidly at speeds above 60 mph. Assume that each 5 mph you drive over 60 mph is like paying an additional $0.20 per gallon for gas. You can improve fuel economy up to one-third by reforming some bad habits, like riding the brake, coming to squealing stops and accelerating like a racecar driver.

Don't "warm up" your car in the wintertime. It doesn't need more than 30 seconds, and just wastes gas. Also, avoid idling - particularly in and around schools or other places where children congregate. Idling allows pollution that contributes to smog (which can trigger asthma attacks) to accumulate right around the car. Imagine a school parking lot full of idling SUVs and school buses! And it's pollution that serves no purpose - you get 0 mpg burning that fuel.

Whenever it is available use the train or bus, and take the subway. The public transportation system in the United States saves 3.4 billion gallons of oil a year, eliminates 541 million hours of traffic delays and cuts greenhouse gas emissions by 26 million tons. As an example, the average Manhattan resident, who has access to subways, buses and sidewalks, produces about one-third as much greenhouse gas pollution as the national average.

If buying a new car, buy a fuel-efficient vehicle. A car that gets 35 mpg will use half as much fuel to go as far as the SUV that gets 17 mpg. An average driver will pay about $900 to drive a 2008 Toyota Prius hybrid for a year, whereas a 2008 Jeep Grand Cherokee will cost more than $4,300.
Check out this list of the ten most fuel-efficient 2008 vehicles!