Acceleration can be express inefficient. Having a awash engine running all the eternity wastes a vast extent of fuel in conventional cars.When a car accelerates, the potential energy inside the gasoline is turned into kinetic energy, or movement. A 3,000-lb. auto rolling along at 60 mph has a lot of energy, but conventional cars have no way to utilize any of that energy. Cars weigh thousands of pounds, and exigency to be able to receive up to highway speeds quickly. Conventional cars appropriateness crowded engines that can ante up a considerable burst of energy when the motorcar needs it to precipitation up. Once the vehivle is at cruising rapidity, on the other hand, the engine sole needs to place absent a bantam bit of capacity to garner the machine rolling. Provided the machine is coasting or rolling downhill, the engine doesn't all the more devoir to be on.
When you stop a car, most of the energy is just converted to heat and wasted. The brake pads rub against the rotor, creating friction which slows the car down. There is no way to store and reuse the energy used to get the thing rolling in the first
place. A lot of wasted fuel happens in city traffic, where a driver might hit the brakes several times every block.
Unlike conventional cars, hybrids use a small, efficient gas engine to generate electricity for an electric motor. The gas engine also produces extra power to charge the battery. The electric motor itself powers the wheels of the car. When it needs extra power to accelerate, the electric motor simply takes more energy from the battery. When the car is cruising or coasting downhill, the motor can generate electricity, or turn off altogether to save energy. The gas engine also turns off when it isn't needed: It will run for long enough to generate power for the motor, the lights and other electronic systems, then turn off to save energy. This saved energy translates into better gas mileage.
Hybrid cars make use of regenerative braking to save more energy. When the driver lets the car coast or hits the brakes, the momentum of the car runs to the generator. This takes some of the kinetic, or movement, energy of the car and turns it into electricity, slowing down the car in the process. That energy is stored in the battery; when the driver hits the gas again, the electric motor can reuse that saved energy. In practice, not all of the energy is saved. Hybrid cars use disk brakes like normal cars to help them stop more quickly. Even so, enough energy is reused to really boost gas mileage.
