Hybrid System Overview

A hybrid vehicle combines a gasoline engine with one or more electric motors. The two power sources work together to move the car, and the vehicle's computer decides which one runs, when, and how much each contributes. The result is better fuel economy and lower emissions than a gas engine alone.

A gasoline engine is most efficient at steady cruising speeds. It is least efficient in stop-and-go traffic — accelerating from a stop, idling at red lights, creeping through parking lots. An electric motor is the opposite. It delivers maximum torque from zero RPM and is extremely efficient at low speeds. A hybrid combines both to cover each other's weaknesses. The electric motor handles the low-speed work where the gas engine wastes fuel. The gas engine handles highway cruising where it is most efficient. Together they burn less fuel than either would alone.

At low speeds and light loads, the electric motor drives the vehicle and the gas engine stays off. Under harder acceleration, the gas engine starts and both power sources work together. At highway cruise, the gas engine drives the vehicle directly while the electric motor may assist or rest. During braking, the electric motor reverses its role and becomes a generator — capturing energy from braking and sending it back to the battery. At a red light, the engine shuts off completely and restarts instantly when you press the accelerator. All of this happens automatically. The driver does not need to do anything different.

Hybrids operate at voltages between 200 and 350 volts on most systems, with some newer designs going higher. The high-voltage components — battery pack, motor, inverter, and cables — are identified by orange cabling. Orange means high voltage. Never open, cut, or touch an orange cable or connector without following the full de-energization procedure. The vehicle also maintains a conventional 12-volt system for accessories and control modules, just like a standard car.