Behind the Scenes: 'Hypermilers' test limits of fuel conservation

In our Behind the Scenes series, CNN correspondents share their experiences in covering news and analyze the stories behind the events. CNN's Miles O'Brien rides with a guru of fuel conservation.

WAUKEGAN, Illinois (CNN) -- Wayne Gerdes is a man on a mission. He wants to end our wasteful ways, and that became plain as day to me from the moment I met him.

He is the king of "hypermilers," drivers who push cars to their miles per gallon limits and beyond. Wayne gets about 50 mpg from his Honda Accord using hypermiling techniques.

We met him at the Waukegan Regional Airport not far from his home. CNN producer Dana Garrett and I had flown there in my small, single-engine airplane, a Cirrus SR22. Within moments, Wayne and I were talking about the kind of mileage it gets.

Fortunately, as air travel goes, it is a pretty efficient mode of conveyance. Once I have leveled off at say 8,000 feet and after, I have "leaned" the fuel/air mixture to the most efficient setting. I usually get about 13 miles per gallon.

Wayne seemed to approve of this and was glad I did not arrive alone. He reminded me miles per gallon per person, or MPGPP, is really the crucial number. That led us to a conversation about the relative benefits of driving versus flying commercially.

Wayne is a nuclear engineer and the kind of guy who runs the numbers. He says for longer trips -- flying on a full airliner is more efficient than driving. Matter of fact, it is not even close. Watch a demonstration of the hypermiling techniques »

Let's run the numbers on the latest model of the Boeing 737-900. The plane burns about 2.4 gallons per nautical mile, and a trip from New York to Los Angeles, California, is about 2,100 nautical miles. So that means it would take about 5,000 gallons of Jet-A fuel to fly coast to coast.

Now let's assume it is configured to hold about 175 people -- and the plane is full -- aren't they all these days? That comes out to 28.5 gallons per passenger. Even if the passengers were all Toyota Prius owners (which get 50 mpg), 28.5 gallons would only get them 1,400 miles down the road. So if the choice is flying -- or driving solo, the airliner wins by a huge margin.

But if you fill the Prius with people -- it becomes competitive with flying. The driving distance between New York and Los Angeles is 2,700 statute miles. That amounts to 54 gallons of gas in the fuel-sipping hybrid. With four people in the car, the Prius wins -- with each passenger using only 13.5 gallons.

As you can plainly see, if you drive a plain old gas-engine car the airliner is more likely to be a more efficient way to travel. If your car gets, say 25 mpg, it will burn 108 gallons to get you to the "Left Coast." With four people inside, your per capita use of fuel is 27 gallons -- or virtually tied with the full 737.

So if you have to be somewhere, and you don't want to waste a lot of gas and make a big carbon footprint, the airlines are probably the way to go.

Now speaking of big footprints, when I finally mustered up the courage, I confessed to Wayne that my main mode of ground transport is what he derisively calls an FSP, or "fuel-sucking pig." It's a 2000 GMC Yukon XL. (I call it the "rolling ZIP code.")

Wayne gave me some lessons in squeezing out better mileage in my FSP. Using his techniques, I was able instantly to increase my mileage by about 30 percent. But even before gas got to be $4 per gallon, I knew the Yukon was an anachronism -- and borderline immoral.

But the FSP is paid off and runs well, so until recently, economics made it smart to keep it. (We don't drive very much in Manhattan.) No question it is now time to move on to something less excessive.

In the meantime, my tires will be pumped to the max, the filters clean, the oil viscosity low and the engine will be off at stoplights.

Wayne has made me a believer.

You can find out a lot more about his techniques at www.cleanmpg.com.

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