St. Thomas Academy students celebrated Sunday after being recognized for building one of the fastest energy-efficient cars in the world.

The teens were in London over the Memorial Day weekend competing against nine high school and university teams in the Shell Eco-Marathon Drivers' World Championship, a competition that "marries the efficiency of the car and how fast it goes," said Caroline Little, the team's faculty adviser.

After crashing their car in the final race of the 2016 world championship in London, the students returned and won.

"This is a much better way of going home," Little said. "To have won this is just so gratifying."

Last year, the students were confident they would be coming home with a prize. The team's car had passed strenuous technical inspections and then completed laps around the racetrack to determine its efficiency. But in the final race, things went downhill.

"It was all very smooth up until the race itself," said senior Jackson Mejia. "The car was completing a hairpin turn, then it rolled over. That ended the race for us."

This year, they sought redemption.

Alex Moeller, a junior, said the team designed a new race car from scratch. The students determined, after analyzing their mistakes, that the car had to be shorter, lighter and wider than last year's model. The driver now sits in the middle of the car.

Sam Westlake, a junior, designed the car using computer software and 3-D printing — shaving about two months off the build time.

"We did reworks in basically minutes without having to do a full-size or scale models," Westlake said.

The car's new specs include four-wheel, independent suspension and hydraulic disc brakes. It weighs 240 pounds and is made primarily of carbon fiber.

For the teens, the win Sunday in London validated missed vacations and weekends spent building their car.

"We started in August," Mejia said. "We're carving foam and doing fiberglass stuff and it's really hard to see at that point what you're working for. We do more work and it starts looking more and more like a finished car. And then you get to London and you are here because of your team's hard work and you win. That's incredibly awesome."

Another Minnesota high school also placed in the competition. Students from Alden-Conger High School in Alden, Minn., placed third.

Twitter: @KarenAnelZamora