Every year, global energy and petrochemical company Royal Dutch Shell challenges high school and university students to design, build and test energy efficient vehicles. Created to spark debate about the future of mobility and inspire young engineers, the Shell Eco-Marathon begins in the Americas, before moving to Europe and then finally Asia. This year's Americas event which took place in Houston, Texas from April 24th-27th, 2014 attracted 121 teams from all across the continent.

The vehicles which can be powered using any energy source - from gasoline, to solar, electric and even hydrogen, are designed with one goal in mind - energy efficiency. That means that they have to be able to travel the farthest distance using the least amount of fuel. In addition to an overall winner, prizes are also awarded in various other categories that include best achievement by fuel choice and overall safety of vehicle. Besides bragging rights, each winning team also takes home a $2,000 USD prize.

To ensure that the vehicles comply with the official rules and specifications, the four-day event begins with a thorough inspection of each car that includes measuring and testing things like height, width track, tire size and even driver weight. While most teams are allowed to enter after a few minor adjustments, some simply don't meet the criteria and have to return home without ever entering the track. Those that pass inspection make their way to the tracks at their respective designated times on the final two days of the competition. Teams are allowed multiple runs and can even adjust their vehicles in between each run, to fix any issues.

This year's top prize was snagged by the futuristic-looking Alérion Supermileage. Built by students from Quebec's Université Laval, the vehicle did not have a very good start to the race thanks to some friction problems in its electrical system. However, the superb student engineering team was able to solve the issue and take home the top prize for a second year in a row, with a stunning 2,824 miles per gallon (mpg). While that was certainly impressive, the team was unable to surpass its own record of 3,587 mpg (the distance from London, England to Cairo, Egypt), that it achieved in 2013. But given that the Canadian University has dominated this competition for five of the six years it has entered, they are sure to return next year, with an even more energy efficient vehicle.

Budding engineers from Mater Dei High School in Evansville, Indiana, won the top honors in UrbanConcept category for the third year in row, with their gas-powered vehicle, Elroy that achieved a stunning 901.48 mpg, easily surpassing its 2013 record of 849 mpg. If that isn't impressive enough, the school's second entry, an electric vehicle won in the Prototype energy category with a mind-boggling 537.16 miles per kilowatt-hour (m/kWh).

Other teams that took home top laurels included Indiana's Sullivan High School whose Black Diesel set a new record with 1,899.32 mpg in the Prototype diesel category. The prize for the most efficient ethanol-fueled car went to the team from the University of Colorado, Boulder, which achieved 1,771.37 mpg with their vehicle, Tatonkatoo. University of Colorado, Denver, took home the top prize in the Prototype hydrogen, with Archetype that achieved a super efficient 37.37 m/kWh.

Among this year's entrants were two all-girl teams - The ShopGirls of Granite Falls High School from Washington state who have been competing since 2010, and The Doves Under the Hood, from St. Scholastica Academy in Louisiana. Though neither won any track awards, the ShopGirls did go home with the Safety Award, the highest off-track honor, for the second year in a row. But neither team was discouraged. Their main goal is to prove that an all-girls team can be serious competitors in a technology driven event largely dominated by males.

Also, while the prizes certainly help, that according to Wolfgang Warnecke, Shell Chief Scientist Mobility, is not the goal of the challenge. He says that the company views the "Shell Eco-marathon as a way to spark a passion for engineering among young people, as well as fuel the conversation around future energy challenges". And with the youngsters coming up with innovative new technologies every year, he hopes that someday, one will be good enough to make its way into everyday vehicles.

Resources: shell.com, fastcoexist.com