Why do I need to accelerate downhill?

Foot off the accelerator is designed to emulate same in automatic transmission car (regen in lieu of engine braking).

To remove that effect, slightly depress gas pedal.

Also, check tire pressure and make sure no brakes are dragging (in neutral, you should not feel any negative g's as you glide).

'Normal' cars vary in how they coast. Prius regen's noticeably unless you fix it with your right foot.

 

As it does this it is regenerating, sending electricity to the big battery. Or as stated above lightly put foot on gas peddal and help it glide.

 

To put it simply, yes. When your foot is off the pedal, the car uses some of your momentum to regenerate the battery. Just about all plug-ins and hybrids do this. Regular cars don't do this as they have no battery to regenerate so coasting is more fuel efficient.


iPhone ?

 

When you let off the throttle in a conventional car, you slow down in part due to compression breaking; the engine compresses the air, but with little fuel (essentially at an idle level). When the air is compressed, it heats up, and that is where the energy goes (wasted). With hybrids, the engine can just be turned off, and the motor-generator put in generator mode to put charge into the traction battery, which can later be used to move the car. Pressing lightly on the throttle tells to control system back off on the generator, so you coast. The throttle is just an input the control system telling it how much power you would like, and has no mechanical connections to anything.

 

I agree that it varies widely in "regular" vehicles. Seems like a good rule of thumb is that the bigger/heavier the vehicle the easier it coasts. (ie. my truck coasted a lot better than a little 4 cylinder I had)