You're probably wrong about fuel economy

Most drivers save more fuel by changing how they drive than by changing cars. The biggest gains come from smoother acceleration, gentler braking, lower speeds and less idling, not gadgets or racing tricks. (epa.gov) The United States Environmental Protection Agency says fuel economy swings with behavior: slow down, accelerate and brake gently, avoid idling, keep tires properly inflated and combine short trips. The agency also tells drivers to use real-time fuel economy displays, if their cars have them, to see which habits waste gas. (epa.gov) The Department of Energy says aggressive driving cuts fuel economy by 15% to 30% at highway speeds and 10% to 40% in stop-and-go traffic. It also says gas mileage drops rapidly above 50 miles per hour, and every 5 miles per hour over 50 is like paying an extra $0.22 per gallon. (energy.gov, energy.gov) That is why one of the most common fuel-saving tips sounds slow rather than fast: look ahead and lift early. The Department of Energy says some fleets coach drivers to coast toward red lights, minimize unnecessary shifting and limit idling to 30 seconds or less. (energy.gov) The advice lines up with what record-setting hypermiler Wayne Gerdes said after a September 12, 2024 coast-to-coast run in a Toyota Prius LE. Toyota said Gerdes averaged 93.158 miles per gallon over 3,211.7 miles from Los Angeles City Hall to New York City Hall and recommended slower takeoffs, steady pedal pressure and easing off early before stops. (pressroom.toyota.com) Toyota also said Gerdes drove through the Mojave Desert in temperatures above 105 degrees, climbed to 7,000 feet and still beat the previous record, which it described as being in the mid-70s miles per gallon. The company said his result was not typical and depended on planning, route changes and hypermiling skill. (pressroom.toyota.com) Some of the “Formula 1” lesson is not about speed at all. Tire pressure is treated as a performance and safety variable in top-level racing, and the Environmental Protection Agency gives the same basic instruction to ordinary drivers: keep tires properly inflated to avoid wasting fuel. (pirelli.com, epa.gov) Another stubborn myth is that restarting a modern car wastes more fuel than waiting with the engine on. The Department of Energy says idling for more than 10 seconds uses more fuel and creates more emissions than stopping and restarting the engine. (energy.gov) The bottom line is less glamorous than most fuel-economy lore: drive smoothly, leave earlier, check your tire pressure and stop burning fuel while parked. For most people, the cheapest mileage upgrade is already under their right foot. (epa.gov, energy.gov)