Winning team in Missouri SuperMileage Challenge. Image courtesy Marcus Reynolds, Aurora Junior H.S.

The next time you fill up your car, watching the tank fill and your wallet empty, you may want to think about the kids in Mr. Reynolds' after-school group at Aurora Jr. High School in Missouri.

They built a car that got 353 miles per gallon to win the 2012 Missouri SuperMileage Challenge. And they're all in seventh or eighth grade.

"I'm pretty proud of them, yeah," said Mr. Reynolds - that's Marcus Reynolds, who teaches industrial technology at the school. "They're sitting on Cloud 9 right now."

The students did not, of course, build a car meant for American roads (12- and -13-year-olds are a bit young for drivers' licenses anyhow). Their car weighs about 100 lbs. and has an engine meant for motorized bicycles. It seats one - three kids, each about 4-foot-11, took turns driving in the competition - and they were not allowed to exceed 30 miles per hour on a closed highway patrol training track.

But they did try some things that might be useful, both to automakers and to you when you're out on the road tomorrow. At times, Mr. Reynolds said, their car got as much as 437 mpg in tests on level ground. Their winning average, 352.5893 mpg, was a third higher than what any of the other seven teams got - and those were high-school kids.

So how did they do it? Their car was streamlined, its three bicycle wheels placed so they wouldn't interrupt the flow of air around the body. It was made of corrugated plastic, chosen to be sturdy and light. Drivers wore helmets and harnesses, and the car had a roll bar for safety on tight turns. The kids suggested features for the car, said Reynolds, and he discussed the pros and cons of each with them.

But what really made the difference, Reynolds said, was the way the kids drove. They learned to "pulse and glide," he said, stepping on the gas pedal every few seconds to keep up speed, but mostly coasting the rest of the time. It's something anyone can do on the road, and some auto companies say it's more efficient than keeping one's foot on the gas all the time.

Aurora Junior High School car on track for Missouri SuperMileage Challenge. Image: Collin Wilson, Aurora Junior H.S.

Reynolds said the project got no money from the Aurora school district, which is in southwestern Missouri not far from Springfield. It relied on donations from around town. Mr. Reynolds recruited 12 kids who he thought had skills that would help the project.

"There were two that I call my mathematicians," he said; others were into taking things apart to see how they worked. One was the group photographer, so he took pictures and kept records.

"They're pretty self-motivated," he said, "and they're people you're going to hear from."