Hypermiling is driving or flying a vehicle with techniques that maximize fuel efficiency. Those who use these techniques are called "hypermilers". In the case of cars, this is an extreme form of energy-efficient driving, where hypermilers can achieve up to in hybrid cars that have EPA ratings of 30 to 45 mpg (48 to 72 km/gallon, 11 to 16 km/L, 6.2 to 9.3 L/100 km).
Hypermiling can be practiced in any vehicle regardless of fuel consumption. It gained popularity with the rise in gasoline prices in the 2000s. Some hypermiling techniques are illegal in some countries because they are dangerous. In 2008, the New Oxford American Dictionary voted "hypermiling" the best new word of the year.
There are various techniques used by gas-powered car driving hypermilers that help increase their gas mileage.
Researchers studying economical driving (or eco-driving) from the University of Belgrade advise on techniques that can be used to minimize fuel consumption while driving, and they include:
Moreover, the same researchers also advise on techniques that can be used to minimize fuel consumption before driving, which include:
Carrying the least amount of weight possible will also aid in less fuel consumed and can add unnecessary weight to the vehicle. Moreover, authors from the hypermiling advice website Hypermiler.co.uk suggest wearing thin-soled shoes can aid in reducing fuel consumption; thinner soles can result in increased sensitivity to the gas pedal.
Hypermiling can also be practiced using relatively lower fuel efficiency vehicles like SUVs. An Edmunds experiment reports that hypermiling could add 35.4% more miles per gallon from a Land Rover LR3, which usually gets in the city and on the highway.
Drafting as a technique for hypermiling has been a subject to controversy. This involves driving close to or slipstreaming behind the car in front, potentially saving 40% of fuel. Drafting can save energy by using the car ahead to push air out of the way. This technique is subject to controversy due to the reduction in visibility and the risk of not being able to brake fast enough if the car in front stops.
The range of electric cars is limited. To get the most out of the battery, drivers sometimes use hypermiling techniques. Some aim to set a record for most mileage from a single charge. For example, a Tesla Model 3 ran more than with one battery charge. The average speed was and the whole drive took around 30 hours. The tester used the autopilot of Tesla Model 3, running the car unmanned. The test car did not drive on a public road.
There have been several aircraft hypermiling competitions held throughout the years, such the FuelVenture and CAFE challenges. Klaus Savier won the 2009 Fuelventure 400 in a VariEze aircraft which got at with a modified Continental O-200 engine upgraded with a computerized fuel injection and ignition system by Light Speed Engineering. By slowing to extend range, mileage approaches .
In World War II the famed pilot Charles Lindbergh consulted with pilots of the Army Air Corps and the Marine Corps and introduced engine-leaning techniques which greatly improved fuel consumption at cruise speeds and enabled aircraft to fly longer-range missions.
In June 2008 at the Michigan International Speedway, Dale Earnhardt Jr. won the Lifelock 400 and shared information about coasting (a hypermiling technique) behind the pace car during the caution flag.
In August 2017, the official Tesla club in Italy, Tesla Owners Club Italia, had five people drive 29 hours in Southern Italty to drive a Tesla Model S 100D a total of on a single charge.
In May 2018, two Colorado residents drove 32 consecutive hours to drive their Tesla Model 3 on a single charge. It beat a previous record of from a Tesla Model S P100D, but it fell slightly short of a 670-mile run in a Model S by an Italian team last August.
In 2018, Frenchman Pierre Desjardins set a record covering of the Périphérique ring road in Paris on a single charge in a 40kWh Renault Zoe, which had an official WLTP range of just , and ended up with a fuel efficiency of per kilowatt hour.
In 2022, a team from the armed-forces charity Mission Motorsport drove two stock 52kWh Renault Zoe cars, with an official range of , at Thruxton Circuit in Hampshire to break the previous Renault Zoe EV hypermiling record. They maintained a speed of , and followed racing lines that offered the path of least resistance. The first car finished at , while the second car finished at , which was more than the Zoe's WLTP range and ended up at per kilowatt hour.
Hypermiling has come under fire from several sides because some hypermilers show dangerous or illegal behaviour, such as tailgating larger vehicles on motorways to save fuel, cycling between accelerating and coasting in neutral, and even turning the engine off when its power is not needed. For this reason, the Hypermiling Safety Foundation was established in August 2008 to promote a safety and education program that promotes legal fuel-saving techniques.
As of 2022, hypermiling may be considered a popular pastime, where there are MPG marathon events and hypermilers share their success in maximizing fuel efficiencies.