This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

Gliding ten laps around downtown Houston in what looked more like a low-riding white rocket ship than a car, a team of students from Université Laval of Québec City marked a new achievement in fuel efficiency this weekend.

For the third straight year, the Canadian team called Alerion Supermileage won the Shell Eco-marathon Americas student design competition; its 2,564.8 mile-per-gallon (1,090 kilometer-per-liter) run beat its own previous year's performance by 77 mpg (33 km/l).

It may seem an unimaginable feat to U.S. drivers accustomed to eking out 22.6 mpg on average, but the two-day Eco-marathon event is a chance for young mechanics and aspiring engineers to demonstrate that fuel consumption can be drastically reduced with lightweight, aerodynamic shape and creativity. In fact, students in the European edition of Shell's Eco-marathon regularly achieve far higher mileage—with the French technical school St. Joseph La Joliverie last year reaching 6,973.4 mpg (2,964.7 km/l).

Teams from 30 universities and 18 high schools from the United States and Canada converged on Houston for Eco-marathon Americas, bringing 69 homemade vehicles to the U.S. oil capital for a weekend of slow-speed, high mileage racing.

Of course, only the most adventure-seeking drivers would welcome a ride in some of the vehicles the students have devised—especially a few that are little more than surfboards on wheels with an engine in back and a Lexan polycarbonate plastic dome on top.

But beginning in 2009, Shell added a new category to the contest, challenging students to design "urban concept" vehicles that meet safety criteria for driving on city streets.

A dozen student teams this year entered urban concept cars in the contest. Louisiana Tech University won the category with a vehicle that had the retro look of a Plymouth Prowler in the front and the futuristic flourish of a Mazda concept car in the rear. Louisiana Tech also took home a separate award for design for its bright red roadster, which achieved an efficiency mark of 647 mpg (275 km/liter).

A Global Competition

The Eco-marathon is meant to echo an efficiency design contest that Shell research scientists waged against each other for a number of years beginning in 1939. The winner of that first contest hit 50 mpg (21 km/l).

In 1985, Shell kicked off the Eco-marathon as a design contest for high school and college students held each year in Europe. Now, the event is a three-continent series. The Europe run is set for May in Lausitz, Germany, and the Asia contest will be held in July in Kuala Lumpur, Malaysia.

Université Laval's team aims to compete in the Europe Eco-marathon next month, with an even more super-charged vehicle. The students had hoped to unveil it in Houston, but the aerospace materials they wanted to incorporate did not arrive in time, said team manager Anthony Bernier, a senior mechanical engineering student.

Following the race, he said he and his teammates immediately face final exams, then graduation from Laval, which is known as one of Canada's leading research institutions and the first francophone university in North America. Then it's back to work on the new car.

What's the secret to the team's success? Says Bernier: "It is basically the whole thing together—the car, the aerodynamics, the engine, electronics, all the components." The car's shell is completely made of carbon fiber—a lightweight super-strong material favored by many Eco-marathon competitors—and it fully conceals the wheels to cut down on wind resistance.

Laval's outing was not flawless; on the team's first run, the car made it only halfway before being sidelined with a broken chain. But near the end of the day on Saturday, driver Mathilde Jean-St-Laurent steered the prototype around the six-mile (9.7-km) course using only 9 milliliters of gasoline. Each car pulls up to a measuring station where technicians in lab coats use pipettes and thermometers to measure the amount of fuel used. (The thermometers account for fuel expansion in the sometimes-blistering engine heat.)

From Haves to Have-Nots

Even before the first Eco-marathon test runs began on Friday, crowds were gathering around the Louisiana Tech stall in the George R. Brown Convention Center to get a closer look at the two buffed urban concept machines—one blue and one red—that they had entered in the race. Junior Sam Ashley, the team manager, described a "grueling two- or three-month process" on bodywork, filling in gaps and sanding the carbon fiber down to a smooth finish.

Explained faculty adviser Heath Tims: "Our goal, even if we don't put up the best stats, is that people will look at it and say, ‘I want that.'" But by the end of the two-day competition on Sunday, Louisiana Tech had indeed put up the best stats among urban concept vehicles. Both the Université Laval and Louisiana Tech teams took home $5,000 prizes for winning their categories, with Tech taking home an extra $1,000 design prize.

Prizes ranging from $1,000 to $1,500 were also awarded for leaders in every category of alternative fuel—hydrogen, solar, "alternative gasoline" (the winners used ethanol), and for the first time in the Eco-marathon this year, plug-in electric vehicles.

There were no limits on how much money a team could spend on its vehicle, so given the ability of some teams to attract major corporate sponsors, differences among the entries were stark.

With the help of sponsors like Lockheed Martin, Exelon and GE Energy, Purdue University was able to pour an estimated $100,000 into a street-legal solar car, Celeritas (Latin for "speed of light," the "c" in the equation e = mc2). On the other end of the spectrum, the team from James B. Dudley High School in Greensboro, North Carolina, a school with many students from low socioeconomic backgrounds, spent no more than $150 cash on its vehicle, says faculty adviser Ricky Lewis. The team's electric car with a cardboard frame was put together with equipment donations from local businesses and recycled junk.

Competing Approaches on Comfort

The teams also had widely varying views on the best way to design for the race. Matt Migliorini, driver for Sullivan High School of Sullivan, Indiana, described his team's low-profile vehicle as "just big enough for a driver and an engine, basically."

On the other hand, the team from Loyola Marymount University of Los Angeles purposefully made its vehicle body wide to give the driver comfort and room. "You notice that some of the drivers are getting so crammed they're getting dizzy from the heat," said team member James Clements, a senior who is headed to Stanford to study for a doctorate in biomedical engineering. "It turns out driver skill and awareness contributes to about 30 percent of fuel efficiency, and so our driver's aware, our driver's comfortable and our driver is able to make good decisions on the road."

Indeed, in their low-slung vehicles with minimal suspension, drivers learned that staying alert was advisable when making the turns around Houston's urban park, Discovery Green. "It's rough," said Mike Reyerson, a senior at Alden-Conger High School of Alden, Minnesota. "You really try not to hit bumps; you pay more attention not to hit bumps than anything else." His team's Green Machine, running on 100 percent ethanol, took second place in its alternative fuel class, winning $1,000 for a 758.8 mpg (322 km/l) run. (First place went to another ethanol team from the heartland, University of Illinois at Urbana-Champaign.)

On the track under the cloudless Texas sky, team members held cardboard or jackets aloft to try to shield the drivers from the sun. Many sweltered in their full racing gear—driving suits, helmets, goggles, gloves—as they waited, one at a time, for the green flag to start their laps.

Once on the track, many of the cars sounded like they were made for cutting grass rather than burning rubber, and least one driver actually started his vehicle by pulling a cord over his shoulder as if he were starting a lawnmower. But instead of the constantly revving engines of a speed race, the noise from the track was intermittent. That's because one of the key fuel-saving strategies is to coast as much as possible (while maintaining the minimum speed requirement.)

Mark Singer, Shell's global project manager for the Eco-marathon, noted, "There's not much rocket science" behind the strategies the student teams use to reduce consumption, such as building lightweight vehicles or becoming more aware of the impact that driving strategies have on fuel burning.