4 ms·

> (gravity is turning the wheels which are turning the engine). ... which brakes the car, so you still lose energy. Can't find literature at the moment, but I

• lmm 10y ago
  Sure. Turning the engine is going to take energy one way or the other. But you can use energy that would otherwise be wasted heating up the brake pads rather than energy from burning fuel.
  • luca_ing 10y ago
    I think the alternative was coasting, not braking.
    • lmm 10y ago
      So if you're coasting you're spending fuel to increase your speed (relative to what you'd do by staying in gear). In the situation where you're considering coasting that's probably not a tradeoff you want to be making.