Driving Down the Heat

You can’t always leave your car at the curb, but you can reduce your contribution to global warming by taking steps to improve your fuel economy

• Heidi Ridgley
• Jan 01, 2005

IN THE LAND where Arnold Schwarzenegger reigns supreme in his Hummer, a new law requiring vehicles in California to gradually emit less pollutants by improving gas mileage has car manufacturers—well—starting to fume. If it stands up in court, the rule might go a long way in fighting global warming, given the Golden State’s environmental pull on the rest of the country.

The law requires reducing tailpipe emissions from carbon dioxide (CO2)—one of the major contributors to global warming—by 30 percent in about ten years. To do this, new cars need to burn less fuel. But while the nation waits for manufacturers to improve mileage standards—which would also increase our national security by lessening our reliance on foreign oil, and reduce pressure to drill in places like Alaska—there are a number of things concerned drivers can do right now to fight climate change, says Jim Kliesch, research associate with the American Council for an Energy-Efficient Economy (ACEEE).

“One of the biggest is to look for the most fuel efficient car available next time you’re standing on the showroom floor,” says Kliesch. And that doesn’t necessarily mean you have to buy a hybrid. “Even modest improvements in fuel economy can make a difference,” he says, “especially when you look outside and see how many light trucks there are on the road.”

For example, buying a shiny, red pickup truck that gets 16 mpg over one that gets 14 mpg can save 134 gallons a year. And because each gallon of gasoline burned pumps out 19 pounds of CO2, it also keeps more than 2,000 pounds of the global warming gas out of the atmosphere.

Of course, the best option—besides your own pedal power—is sliding behind the wheel of a hybrid car, which can get up to 60 mpg. But despite the hybrid’s growing appeal, SUVs are still the vehicles that a majority of Americans hold dear. According to ACEEE statistics, every two seconds a new vehicle is purchased in this country—and every other one of them is an SUV or pickup truck. The popularity of these vehicles has resulted in a 20 percent increase in CO2 pollution since the early 1990s.

But just because it’s an SUV—which can spew up to 43 percent more greenhouse gas emissions than the average car—doesn’t mean it should have a license to guzzle, says David Friedman of the Union of Concerned Scientists. “Today, unbelievably, the average SUV gets worse gas mileage than Ford’s Model T,” he says. “We should be able to do better than that, and the reality is we can.”

In fact, technology exists today that can increase the nation’s average fuel economy from 24 mpg—a 20-year low—to 40 mpg in the next ten years without changing the look, size or performance of the nation’s fleet, says Friedman. And raising overall fuel economy by 10 percent could cost as little as $465 a vehicle, according to a 2001 National Academy of Sciences panel. “That we are still producing vehicles as inefficient as they were 20 years ago is pathetic,” says Kliesch. “Compounding this problem, we are driving more miles than ever before.”

Vehicles in the United States release more CO2 pollution than the entire country of India emits from all its sources—electricity, heating, factories and vehicles—combined. Americans also burn a quarter of the world’s oil, according to Environmental Defense statistics, and 40 percent of that is in passenger vehicles—8.7 million barrels a day.

So what’s an environmentally aware driver—who’s not in the market for a new car—to do? For starters, drive the speed limit. “Driving 75 mph instead of 65 mph decreases fuel economy by 10 percent,” says Kliesch.

Other tips offered by ACEEE include:

Drive gently. Flooring it and breaking abruptly can reduce gas mileage by as much as 33 percent—and increase emissions. One second of high-powered driving can produce nearly the same level of CO2 as a half hour of normal driving.
Get junk out of your trunk. Carrying around extra weight reduces fuel economy.
Go into overdrive on the highway, or if you’re driving a manual, upshift as often as you can. Running the engine at a higher rpm burns more fuel.
In hot weather, don’t blast the air-conditioning right away. Drive with the windows open for 30 seconds to cool off the car before turning on the air.
Monitor your fuel economy every couple of weeks to see if something could be amiss. “For example,” says Kliesch, “you could have a faulty oxygen sensor and you would’ve never known.”
Replace air filters regularly. It can improve gas mileage by as much as 10 percent.
Buy “low rolling resistant” tires. Designed to move the car forward more efficiently, they can improve gas mileage by as much as two miles per gallon.
Keep your tires inflated. Tires lose a pound of pressure each month, and every three pounds below the recommended pressure causes fuel economy to drop by 1 percent.
Park in the shade in summer to minimize evaporation of fuel.
Turn the key and go. Unlike older cars and trucks, modern vehicles don’t need to warm up.
“Such small percentages may not sound like much,” says Kliesch, “but it adds up, especially if you’re going on a long trip.” And that’s fuel for thought—whether you’re Kerouacing it across the country this summer or just continuing down the road on your same old daily commute.