[4] Hypermiling has come under fire from several sides because some hypermilers show dangerous or illegal behaviour,[5] 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.
[8] Even wearing thin-soled shoes can aid in reducing fuel consumption; thinner soles can result in increased sensitivity to the gas pedal.
This involves driving close to or slipstreaming behind the car in front, potentially saving 40% of fuel.
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.
[12] Klaus Savier won the 2009 Fuelventure 400 in a VariEze aircraft which got 45 mpg‑US (5.2 L/100 km; 54 mpg‑imp) at 207 mph (333 km/h) with a modified Continental O-200 engine upgraded with a computerized fuel injection and ignition system by Light Speed Engineering.
[14] 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.