Fuel efficiency

The Celera 500L is a truly remarkable design. Otto Aviation says its odd shape delivers an astonishing 59% reduction in drag, so it can cruise as fast as a small jet while using 80% less fuel. Now, Otto and ZeroAvia are giving it a clean powertrain.

Zero-emissions airliners are still a long way off, but Lufthansa and BASF have developed a way to improve things right now. AeroShark is an adhesive riblet film that immediately reduces fuel consumption, and therefore emissions, from any aircraft.

French company Airseas has installed its first half-size automated Seawing kite to a cargo ship chartered by Airbus, and will commence six months of trials in January. The full-size kite is estimated to save up to 20 percent of fuel burn and emissions.

Ordinarily, airliners have to run their engines in order to taxi along the runway – this uses a lot of fuel, plus it generates a lot of CO2. A new in-ground towing system, however, offers what could be a more efficient and eco-friendly alternative.

Electric vehicles have come a long way in the last decade or so, moving people from A to B with ever-improving efficiency, but none quite match the levels of a student-built railroad car called Eximus IV, which has just set another record in Sweden.

Otto Aviation claims its bizarre-looking Celera 500L "bullet plane" offers the performance of a small jet using just 1/8th the fuel, for around 1/6th the running costs. The company wants to make private air travel cost as much as an airline ticket.

Airliners can make a lot of noise and use a lot of fuel when they're coming in for a landing. A new onboard computer system, however, was recently shown to be effective at addressing both problems.

Everyone knows that walking on soft sand is more difficult than walking on a hard sidewalk. By the same token, MIT scientists are now suggesting that if road surfaces were to be made stiffer, large trucks would use less fuel.

Airbus' new fello-fly demonstrator project will test the idea that two commercial aircraft flying in tandem can boost flight efficiency while reducing emissions, based on the technique used by flocks of birds.

Aptera says it plans to have a car on the road by 2022 that can squeeze 1,000 miles (1,600 km) out of a 100-kWh battery.

The gasoline age is giving way to electric, but there's still plenty of room for last-gasp improvements to the combustion engine.

Once a year, the Delsbo Electric contest in Sweden challenges students to create and improve on the world's most energy-efficient vehicles. This year's champ, the Eximus IV, smashed the competition and all previous records with an electric equivalent of 687 MPGe (0.34 l/100km​).