We Americans drive an average of 10,000 miles per year. Unfortunately, most of our cars are not very efficient.

The U.S. has the worst fuel efficiency of any car-producing country. Most U.S. cars get around 20 miles per gallon. For each mile driven, one pound of carbon is pumped into the atmosphere. That adds up to 10,000 pounds of carbon per car per year. For every 5 mpg better fuel efficiency your car gets, you produce about 300 pounds less of carbon.

If you want to reduce your carbon imprint on the planet, simply reduce the number of miles you have to drive every year.

You may ask why don't we have cars on the market that get 100 mpg? In this age of Hummers equipped with global positioning systems and limousines with hot tubs inside, I don't think 100 mpg is too much to ask. There are moments in my Toyota Prius when I'm coasting downhill, and my onboard computer says I'm getting 100 mpg. My heart beats faster and I get a little thrill until I have to go up the next hill. Like the other 260,000 Priuses on the road today, the Prius I drive averages 46 mpg. Most cars on the road today average less than 25 mpg. The most fuel-efficient car on the market gets 66 mpg - the Honda Insight.

Toyota has announced that its 2009 Prius will get 100 mpg. Toyota is in a hot race with Honda to be first to break the American 100 mpg barrier. Other manufacturers cite costs involved in manufacturing as an obstacle to meeting this goal. They say that the resulting highly fuel-efficient vehicles would cost more than $100,000 each. That's well out of most consumers' price range.

What needs to happen to get 100-mpg cars in the picture is strong government incentives for consumers to purchase them, and subsidies to offset their manufacture. This is not so far-fetched; it's how large-scale chemical agriculture has taken hold. The government subsidizes agro-industries to the tune of $433 per family, according to the U.S. Census.

NEW DESIGNS

Automakers say that cars have to be lighter to be more fuel-efficient. That means more aerodynamic designs, skinnier and harder tires, a smaller engine and lower overall weight. Reducing the weight of a typical light-duty vehicle by 10 percent would increase the fuel economy by 7 percent. That means we should be making cars out of carbon-fiber composite material instead of steel.

A low-volume production run of carbon-fiber composite would cost about $100,000 for the initial model, according to John Fox Rubin, chief executive of Fiberforge, a composite manufacturer in Colorado. Yet producing 50,000 of these copies per year would lower the costs to a reasonable $4,000.

However, large automakers are not doing the cutting edge of fuel efficiency research - backyard mechanics are. There are many hybrid owners who have modified their vehicles to get 100 mpg or more. Steve Lapp in Ontario, Canada, put solar panels on the roof of his 2001 Prius to recharge the battery pack. He gets more than 100 mpg. Pete Nortman, from Monrovia, Calif., has invented a plug-in kit for the Prius. The EDrive kit will debut by December with a price of $12,000, installation included.

The California Cars Initiative, a Palo Alto, Calif., nonprofit, holds public plug-in demonstrations in the Bay Area and predicts a market for as many as 100,000 plug-in vehicles one day.

Ecologically speaking, probably the best solution to getting 100 mpg is to convert a fuel-efficient diesel into a gas/electric hybrid using lithium ion batteries like the ones in cell phones. Mercedes Benz's Smart ForTwo CDi already gets around 60 mpg, and could easily get 100 mpg with a battery-power conversion kit. The diesel engine could be converted to pure vegetable oil to further improve emissions.

What can you do today to get better mileage?- Keeping your car in top mechanical condition. Dirty spark plugs, dirty air or fuel filters will hinder your car's efficiency by as much as 30 percent.

- Keeping the proper amount of air in your tires will save you up to 3.3 mpg.

- A tune-up usually pays for itself, considering you can save about $150 in gas costs.

- If you keep it at a steady 55 mph instead of 70 mph or more on the highway, you save up to 20 percent of your fuel costs. The most fuel-efficient speed is between 45 mph and 55 mph for most vehicles.

- Invest in hybrid technology for your next car.

- Demand more fuel-efficient vehicles at the show rooms.

- Call your representatives and tell them to "bring back the electric car, or support alternatively fueled vehicles."

- If you drive a hybrid already, go to www.edrivesystems.com and add a plug-in option.

Better yet, park the car and walk or bicycle for better health and the best possible mileage.

Shawn Dell Joyce is a sustainable artist who lives in a green home in the Hudson River Valley of New York.

© Copley News Service