How easy is it to achieve better-than-estimated fuel economy?
What hypermilers are doing: Many hypermilers overinflate their tires a couple psi, something that can be dangerous, especially on older tires.
What hypermilers are doing: Passengers? They can walk. Take out all seats except for the driver’s. Don’t forget to lose the spare tire and jack. That’s what AAA is for.
What hypermilers are doing: Park downward facing hills in parking lots or on the street to get a rolling start in neutral instead of needing to use the gas.
What hypermilers are doing: Turn off your air conditioning and roll up the windows. Air conditioning uses engine power and the windows up minimizes wind resistance.
What hypermilers are doing: Never brake at all by coasting to complete stops. Keep (sometimes high) speed around corners in order to maintain coasting out of the turn.
What hypermilers are doing: While gliding, put the car into neutral and wait until you hit a low speed of about 15 mph under the speed limit. Shifting into neutral increases fuel efficiency, but means you don’t have complete control of your vehicle, which is dangerous and illegal in some states.