RAPID CITY, S.D. (AP) — A pair of students at the South Dakota School of Mines and Technology has won two awards totaling $10,000 in prize money for an invention they claim may improve vehicle fuel efficiency by up to 10%.

Sophomores Mark Rotert and John Parker Chandler IV won a combined $5,000 Friday after pitching their vortex generator, TwisTech, in the governor's Giant Vision competition, the Rapid City Journal reported. They also won another $5,000 prize from the college earlier this month for the invention to reduce drag on vehicles.

The students used a 3D printer to manufacture prototypes of the pocket-sized device. They first developed the idea for TwisTech during a national student race car design competition, Formula SAE.

They've since tested it on their personal cars, and used simulation software to test a digital model, they said.

The pair said that the invention yielded a 10% improvement in fuel consumption on sedan-style cars and a 7% improvement on semi-trucks.

Vortex generator devices are most commonly used to reduce drag on airplanes.

"We're now looking at ways to get it into a wind tunnel and get some real world, professional data," Chandler said.

Rotert added that they plan to spend the summer trying to further validate the invention's design.

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