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Driving to glory on a few drops of fuel

The event’s focus on fuel economy is timely in this era of rising energy demand, questions about future supplies and worries over climate change. While the world’s supply of traditional hydrocarbons is finite, transport needs are growing relentlessly. China, for example, has 40 million cars today. By 2020, it could have 140 million, estimates China’s communications ministry. Fuelling them will require an extra 2-3 million barrels of oil per day, about the current demand of Germany, the world’s fourth-largest oil consumer.

Baudoin is the driver of Microjoule, a sleek white torpedo carefully designed to slice through the air. He was one of more than 3,000 students representing 250 teams competing in the European Eco-marathon in France in May. This year an Asian team – from the National University of Singapore – joined for the first time, bringing the number of nationalities represented to 20.

Baudoin’s team from a French technical school, St Joseph la Joliverie, had a reputation to live up to coming into this year’s competition. Over the years the team has amassed a string of victories, including six world records and first place in 2006 when their car went the equivalent of 2,885 kilometres on a litre of ethanol (6,786 miles per gallon). Its success was hard won: back in 1985 at the first European Eco-marathon in France, the team’s vehicle ground to a halt with engine failure after just 100 metres (328 feet).

In the paddocks, teams of students are tinkering with their cars. Some resemble oversized pencils with wheels attached. Others sport iridescent blue solar panels that look like insect wings. Germany’s Ecoemotion’s team has built a car almost entirely out of wood, silk and natural resins which runs on ethanol. All of the cars are equipped with tiny engines, some home-made, others borrowed from lawnmowers.

There are several keys to achieving good fuel economy. One is having a lightweight vehicle. Eco-marathon teams go to extraordinary lengths to keep weight down, building the chassis out of everything from balsawood and bamboo to carbon-reinforced honeycomb and foam-based materials. Wheels and other components are often borrowed from featherweight racing bicycles. Microjoule, for instance, weighs just 30 kilograms (66 pounds).

Teams also seek engine technology that will help them squeeze the most energy out of their fuel. For instance, the National University of Singapore team used an electronic fuel injection system provided by a military research body that adapts to temperature, fuel quality and the outside air pressure. The team from the Technical University of Denmark, meanwhile, devised a fuel cell that converts 100% of its hydrogen fuel into electricity, up from the typical 95% – a system so unique the team was able to patent it.

Smooth aerodynamics translates into lower fuel use, too. Designers try to reduce drag by making their cars sleek and ground hugging. For example, la Joliverie’s team sought assistance from a naval engineer named Gilles Desquilbet who helped design Microjoule to resemble a water drop. After fine-tuning the car’s shape in four wind tunnel sessions since 1987, it slips smoothly through the air. At 30 kph, the three-wheeled car has just 3% of the wind resistance of a typical passenger car such as a Honda Civic and only 1% of a bulky Hummer H2.

Driving technique

Finally, driving technique always plays a crucial role. That means knowing the terrain. The Joliverie team studied an aerial photograph of the Paul Armagnac circuit in southern France before they arrived. The tight, twisty track has a reputation among professional racers for being technically challenging.

After the team’s arrival at the circuit, Baudoin first explored it on foot. Then a test-run by car showed that the constant bends demand a precise trajectory to maintain a regular speed. To complete the contest’s seven laps at the required average minimum speed of 30 kph, the Joliverie team calculated their car’s engine only needed to run for 24 seconds per lap, and only at four strategic places on the circuit.  

Of course, switching off the engine in a modern passenger car is a recipe for trouble, as the steering wheel and brakes would become sluggish. Indeed, at first glance the Eco-marathon’s exotic vehicles and oddball driving techniques have little in common with everyday driving. However, there are clear lessons for the real world. Just look at Australians John and Helen Taylor, who recently drove 29,000 kilometres (18,019 miles) around the world on less than 40 tanks of fuel, earning a new entry in the Guinness Book of World Records. To accomplish that feat, the couple employed a variety of techniques, including smooth driving, keeping their engine speed down and carefully planning the shortest route.

“The Eco-marathon puts efficiency on the agenda, because efficiency is the cheapest way to save energy and to decrease carbon dioxide (CO2) emissions,” said Rolf Hagman, senior research engineer from Norway’s Institute of Transport Economics who was watching the event. “The only problem is that this solution is not very sexy.”

Some 54% of oil consumed in 2006 was used for transport, according to the International Energy Agency. Only around one-eighth of the energy content of fuel in an average passenger car is turned into useful work at the wheels. Of this, most is needed to accelerate the mass of the vehicle, about one-third to overcome wind resistance, and the remainder is used in idling and to overcome losses in the tyres and internal friction.

The transport sector is also responsible for 21% of global CO2 emissions. An average passenger car emits 223 grams of CO2 per kilometre. Microjoule, by comparison, achieved the equivalent of 22.9 grams of CO2 per kilometre, well below the cap of 120 grams per kilometre proposed by the European Commission for all new cars by 2012.

Burning midnight oil

Back in la Joliverie’s paddock – a large tent with a wooden floor – Baudoin fidgets with a small object he carries when he drives. It is a lead weight to ensure he weighs the minimum 50 kilograms (110 pounds) required for drivers. The temperature reached about 50 degrees Celsius (122° Fahrenheit) inside the car during his first drive in the hot spring sun. “You lose weight between tries,” he explained.

One student is fixing Microjoule’s horn, which annoyingly honked for half a run after its circuits melted. Others of the 40-strong team are tuning the car’s hand-crafted engine, which lies on a bench, wired to two laptop computers and other monitoring instruments. The engine is encased in yellow insulation and has a water-filled temperature control system to keep it at an optimum 100°C (212°F) during the sections of each run when it is turned off. Second-year student Jean Dupont checks the fuel system. Meanwhile Stephane Depagne sits at a wooden bench in the back of a truck amid pliers, nuts, bolts and a can of soft drink, soldering the circuits of an onboard computer that control fuel and oil injection. The team will work into the early hours of the morning, preparing the car for the next day’s run.

Nurturing talent

The Eco-marathon is about more than fuel efficiency. It is also about nurturing a new generation of technical experts who will help find solutions to address society’s energy challenges. Over the next five to 10 years an increasing number of experienced engineers at science and engineering-based companies will reach retirement age. At the same time the pool of young engineering graduates is getting smaller, particularly in Western Europe and North America as science-based subjects have fallen in popularity. Almost as many engineering students currently graduate each year from universities in Asia as in Europe and the USA combined. The dearth of engineering talent in the West has led companies to seek graduate recruits in talent-rich countries like India, China and Russia.

The Eco-marathon has in the past proven to be a stepping-stone to jobs for some students. Several were hired by companies such as Bosch or Michelin and bearing maker SKF. And Shell received 60 job applications from participants after last year’s event. “Working on Microjoule helped me get a job,” said Yann le Moval, a recent la Joliverie graduate who now works for French carmaker Renault. “I demonstrated my passion for automobiles and I learnt about teamwork.”

New record

Despite the near accident that forced Microjoule to slow down on the first attempt, Baudoin piloted the car the equivalent of 2,981 km on a litre of fuel (7,013 miles per gallon) – good enough to take the lead in the competition. On a second try later the same day, however, windy conditions forced Baudoin to use more fuel and he was unable to match the first run’s performance. Later that afternoon the winds increased to as much as 30 kph and the team worries that there will be no sense in making another attempt the following day. 

However, the wind subsides overnight and it looks like Microjoule will ride after all. There’s only one hitch: the car’s engine is running poorly. The team scrambles to identify the problem, changing the spark plugs and onboard computer settings, but to no avail. With time running short, the team decides to replace the engine with a spare one. The fix works, and Microjoule secures first place, setting a record for petrol engines at the European Eco-marathon by driving the equivalent of 3,039 kilometres on a litre of fuel (7,149 miles per gallon).

The team from Singapore, meanwhile, was less fortunate in its rookie year at the competition. Their car failed to complete a single lap after a transmission bearing failed. Attempts to repair it were unsuccessful. But the disappointing result only stiffened the team’s resolve. “Next year, we’ll be back,” vowed driver Yeo Yicong.

Discover more: Behind the wheel at the Eco-marathon