This week some of the world’s top engineering students converge at the New Hampshire Motor Speedway to race hybrid cars. The cars are student designed and built, and for some of those students, a good showing at Loudon is a ticket to ride.

Most gear-heads want their cars to sound like finely the tuned performance machines that normally power around the loudon race track and not like over-sized lawnmowers.

But the forty teams of race car builders have come to New Hampshire to compete in the world’s premier competition for student built hybrid race cars, and they aren't worried about how the cars sound.

The students spend thousands of man hours to design and assemble their cars. Ira Goldberg -- with the University of Michigan -- says for the last six months his team has been living and breathing their car.

"We’ve had our struggles along the way." Goldberg recalls, "We’re working trying to get our car finished and together, it’s been very complicated, down the homestretch we’ve had people there just 24 hours. I know that some people have slept in our project center."

Teams compete in a bunch of categories, acceleration, cornering, and even a mock pitch to investors for their design. But most of them are hoping to win the crown jewel for hybrid racers: the endurance event. In that race, each car gets a set amount of “energy” at the beginning: so if one car has more batteries it gets less gas, and vice versa.

The goal is to finish the race as fast as possible without running out of gas, but Doug Fraser, the event's organizer, says "if they finish with a lot of fuel left in their tank because they’ve wasted it, because they could have used it to go a little faster."

He says two years ago an Italian team won the competition after carefully recalibrating their machine to American gas.

Fraser says, "when they came in from the end of the endurance event, there wasn’t a thimbleful left of fuel in their tank."