Team Luk Jao Mae Khlong Prapa from Thailand surpassed their own fuel efficiency record from last year by 31 percent to clinch the top place at Shell* Eco-marathon Asia, which concluded on July 7.

The students from Dhurakij Pubdit University, whose prototype car runs on ethanol, improved their mileage from 2,213.4 kilometers per liter (5,206.2 miles per gallon) to 2,903 km/l (6,828.3 mpg) this year.

Team adviser Dr. Narongdech Keeratipranon attributed the students’ success to their modification to the car’s engine, bearings, tires, air fuel ratio and driving techniques.

“All the work is done by the students. They designed and created their own engine, adjusted the bearings and tires to reduce friction between the vehicle and the road so that the car can go further,” said Dr. Narongdech at the paddock shortly before the award ceremony.

He was speaking on behalf of his students, who were less well-versed in English.

The computer engineering lecturer added that the students would switch off the engine to conserve fuel during the race and only restart it when needed. The longer the car can cruise along the track with its engine off, the lesser the fuel it consumes.

When asked why they picked ethanol as their fuel source, Dr Narongdech said it is renewable and Thailand, one of the world’s leading sugarcane exporters, is looking to tap into the growing market potential of this biofuel.

More than 119 teams from 18 countries around Asia participated in the competition this year and 109 teams passed the technical inspection to go on track.

The Gasoline Fuel Award went to Team ATE.1, from Kong Thabbok Upatham Changkol Kho So Tho Bo School in Thailand, for the second year in a row, but their fuel efficiency record dropped from 1,607.9 km/l (3,782 mpg) in 2011 to 1,120 km/l (2,634.4 mpg) this year.

Team Zeal Eco-Power from Tongji University, China won the Diesel Fuel Award with a mileage of 363.4 km/l (854.8 mpg) but it is also lower than the mileage of 564.2 km/l (1,327.1 mpg) set by NTU Diesel Car Racing Team from Singapore’s Nanyang Technological University last year.

Indeed, it seems some of the best mileage recorded at Shell Eco-Marathon Asia this year was dominated by vehicles powered by biofuel instead of conventional gasoline and diesel.

For instance, the Clean Diesel Team from Japan achieved a fuel efficiency rate of 1,186.6 km/l (2,791 mpg), exceeding their 2011 record of 1,156.6 km/l (2,720.5 mpg), to win the Alternative Diesel Fuel Award for the second year in a row.

Their advisor, Toshinari Fujii from Hyogo Prefectural Tajima Technical Institute, said they had chosen their fuel, which is made up of cooking oil and methanol, because it is carbon-neutral and cleaner, as it does not produce exhaust smoke.

The automotive engineering expert said they had purchased a diesel engine and modified it, including changing the air fuel ratio and injection time to improve fuel efficiency.

In addition, he said the best mileage they have recorded was 2,213 km/l (5,205.3 mpg) last summer in Hiroshima, Japan where the road was flat. The Sepang International Circuit, where Eco-marathon was held, has a more difficult and hillier course.

Fujii said biodiesel has been adopted by bus companies and cars in a few Japanese cities like Kyoto, but barriers to its adoption, such as the collection of used cooking oil and its slightly higher fuel cost, remain and need to be overcome.