The Eco-Marathon is an annual competition sponsored by Shell, in which participants build special vehicles to achieve the highest possible fuel efficiency. The Eco-Marathon is held around the world with events in Finland, France, Germany, The Netherlands, Japan, and the USA. The event also took place in the UK until 2010.
The events are entered by a range of participants from enthusiastic amateurs to university teams and major motor manufacturers with a variety of designs.
A world record was set by a French team in 2003 called Microjoule with a performance of 10705 mpg-imp (0.026388 L/100 km; 8,914 mpg-US). The current record is 12665 mpg-US (0.018572 L/100 km; 15,210 mpg-imp), set in 2005 by the PAC-Car II. The world record in diesel efficiency was achieved by the Spanish team of the politechnical University of Valencia in 2010 with 1396.8 kilometres per litre. In contrast, the most efficient diesel passenger cars achieve 60 mpg-US (4 L/100 km; 72 mpg-imp), and some high-powered sports cars achieve as little as 8 mpg-US (29 L/100 km; 10 mpg-imp).
The event's history stretches back nearly seventy years. In 1939, a group of Shell scientists based in a research laboratory in Wood River, Illinois, USA, had a friendly bet to see who could drive their own car furthest on one gallon of fuel. At the time, 21.12 km/L (59.7 mpg-imp; 49.7 mpg-US) was the best that could be achieved.
- 149.95 MPG with a 1947 Studebaker in 1949
- 244.35 MPG with a 1959 Fiat 600 in 1968
- 376.59 MPG with a 1959 Opel in 1973.
That idea was the foundation for the first international competition held in Mallory Park in the UK in 1977, (1976 international competition "Pisaralla Pisimmälle" was held in Finland (Keimola)).
Over the past 30 years, fuel economy has improved dramatically.
The current European Shell Eco-marathon  record for a combustion engine entry was set in 2004 by the team from Lycée La Joliverie (France) at 3,410 km on the equivalent of a single litre of fuel. For prototype vehicles using fuel cells, the record is even more impressive. In 2005, the hydrogen-powered vehicle built by Swiss team ETH Zurich achieved a projected 3,836 km on the equivalent of a single litre of fuel. This is the equivalent of driving from Paris to Moscow.
According to a Sunday, March 31, 2013 online Associated Press (AP) article that appeared on the Peoria Journal Star's website, for the 2013 Shell Eco-Marathon competition in Houston, Texas, the Champaign-Urbana News-Gazette reported that a group of students from the University of Illinois at Urbana-Champaign (with a $56,000 budget and support from the College of Engineering and several corporations) has designed a two-passenger car, with a hydrogen fuel cell (and with a chassis weighing less than 70 pounds), that could potentially reach a fuel efficiency level of up to 100 miles per gallon.
The Eco-Marathon has different classes of competition: Fuel cell-powered, solar cell-powered, gasoline-fueled, diesel-fueled, and LPG-fueled. During the competition, cars must attain an average speed of at least 15 mph (23 km/h) over a distance of 10 miles (16 km). The course is typically a motor racing track—for the pan-European meet, the Circuit Paul Armagnac in Nogaro, France,The UK event no longer takes place but was formerly held at Rockingham in Northampton, and in the Americas the competition formerly used the course at the California Speedway in Fontana. Though now the Americas automobile competition takes place at Discovery Green in Houston, Texas. The fuel is strictly measured out for each entrant. At the end of the course, the amount of fuel used is measured; from that figure, fuel economy is calculated.
The marathon includes a set of rules to create a set of safe conditions for the event. Some of the rules for the event may encourage participants to enter vehicles that use hydrocarbon-based fuel sources. For instance, the Eco-marathon places solar-powered vehicles in their own class and are excluded from winning the $10,000 grand prize.
The top performing vehicles are specially designed for high efficiency. Some vehicles use a coast/burn technique whereby they briefly accelerate from 10 to 20 mph (from 16 to 32 km/h) and then switch the engine off and coast for approximately 2 minutes until the speed drops back down to 10 mph (16 km/h). This process is repeated resulting in average speed of 15 mph for the course. Typically the vehicles have:
- Automobile drag coefficients (Cd) < 0.1
- Rolling resistance coefficients < 0.0015
- Weight without driver of < 45 kg
- Engine efficiency of < 200 s.f.c. (cc/bhp/hr)
The vehicles are highly specialized and optimized for the event and are not intended for everyday use. The designs represent what can be achieved with current technology and offer a glimpse into the future of car design based on minimal environmental impact in a world with reduced oil reserves. The work of the participants can be used to show ways manufacturers could redesign their products.
Teams who have participated in the competition include
- Team PNEC - National University of Sciences & Technology Pakistan
- Team HammerHead-Ghulam Ishaq Khan Institute Pakistan
- DTU Roadrunners - Technical University of Denmark 
- Purdue Solar Racing 
- Darien Fuel Cell Team 
- Cal Poly Supermileage, from California Polytechnic State University
- Cedarville University
- Team H2politO - Molecole da Corsa 
- Team Green 
- Eco-Runner Team Delft 
- Trinity School Racing 
- University of British Columbia - UBC Supermilage 
- Aemval 
- Sandbach School 
- Team Schluckspecht 
- Team TIM 
- Fortis Saxonia 
- Eco Motion Team by ESSTIN 
- Remmi-Team, Tampere University of Technology, Finland 
- Team Economus
- University of Ottawa Supermileage
- Team EcoCar by Louisiana Tech University 
- The Politechnical University Of Valencia
- The Leekburners, Lindenborg High School, Leek, Netherlands (http://www.leekburners.eu)
- DNV Fuel Fighter - Norwegian University of Science and Technology, NTNU 
- EcoCars by Royal Institute of Technology KTH 
- The Hydro Cruisers (The Hague University) 
- The Harwich School
- Tigergen II by the University of Missouri 
- The Green Machine by the Vrije Universiteit Brussel and the Erasmushogeschool Brussel 
- Pak Pacers - University of Engineering and Technology, Taxila, Pakistan
- The Y-Nots! - Air University, Islamabad, Pakistan
- Rakata Team - Bandung Institute of Technology, Indonesia
- SEMAR UGM TEAM - Gadjah Mada University, Indonesia
- Simpson, Richard (2003-07-18). "Running on empty". The Daily Telegraph (London: Telegraph Media Group). Retrieved 2008-10-20.
- "Lowest Fuel Economy Models: 2010 Model Year". United States Environmental Protection Agency. October 19, 2009. Retrieved 1 March 2010.
|Wikimedia Commons has media related to: Shell Eco-marathon|
- Official Shell Eco-Marathon website
- Website/blog of the Cal Poly Supermileage Team
- The University of Strathclyde Eco-Marathon Team
- PV3e: a Shell Eco-Marathon team
- Sandbach School's team video
- Team Toulouse Mechanical Engineering
- University of Ottawa Supermileage
- Blog of the Eco Motion Team by ESSTIN
- Hybrids, meet your rival -- it gets 376.59 mpg
- H2PolitO - Molecole da Corsa Website
- Pictures of Shell Eco-Marathon
- Official Website of TEAM PNEC
- DNV Fuel Fighter - Norwegian University of Science and Technology