An original hybrid approach delivers both
environmental responsibility and fun driving

As a mobility manufacturer dedicated to helping solve the critical issue of CO2 emissions, Honda has for decades been engaged in developing a full range of vehicle electrification technologies. As part of this initiative, Honda is further expanding its lineup of hybrid vehicles, which are currently among the most accessible electrified vehicles.

Hybrid technology improves fuel economy by efficiently using two sources of power: a motor and a gasoline engine.

The e:HEV hybrid system combines all of Honda's gasoline engine and electrification technologies with an array of other advanced technologies to achieve exceptionally low fuel consumption and a new level of driving pleasure.

While a motor operate throughout the low- to high-speed range, e:HEV relies on the gasoline engine alone for high-speed cruising. Through this configuration, the system realizes a unique combination of environmental performance and driving pleasure that could not be achieved with an engine-only system.

Honda's unique e:HEV hybrid
combines the best of motors and engines

While a gasoline engine can produce high output at high rpm, it has difficulty generating torque at low speeds, such as when starting off, and its fuel economy is poor in the stop-and-go traffic of city driving. In contrast, a motor can generate maximum torque even at low speeds, including when starting off. Hybrid vehicles improve efficiency and fuel economy by using two different sources of power: motors, to high speeds, and gasoline engines, which excel at high speeds.

Around the world, automakers have developed a wide variety of hybrid systems, matching them to models based on size and other factors.

In general, there are three types of hybrid systems: the series hybrid system, in which the gasoline engine generates electricity and the motor alone provides power to the wheels; the parallel system, in which the engine is primarily responsible for providing power to the wheels and the motor assists; and the series/parallel system, in which both the engine and motor can provide power to the wheels.

At low to medium speeds, at which the motor excels, e:HEV operates as a series system, providing power to the wheels with the traction motor alone. In high-speed cruising, in which the gasoline engine excels, e:HEV operates as a parallel system, simply connecting the engine directly to the wheels to provide power. Unique to Honda, this innovative hybrid system leverages the best features of both the series and parallel systems.

■ Differences between e:HEV and other hybrid systems

Differences with series/parallel hybrid system

A series/parallel system adjusts the ratio of power provided by the gasoline engine and motor based on driving conditions. In contrast, e:HEV depends mostly on more efficient motor power in daily driving, switching as needed between EV Mode and Hybrid Mode. Thanks to its simple structure with no complicated power-dividing mechanism, e:HEV can leverage its traction motor to maximum effect and deliver both outstanding performance and efficiency.

Differences with series hybrid system

A series hybrid system uses the gasoline engine to generate electricity and the motor to drive the wheels. In high-speed cruising, the motor operates with reduced efficiency, requiring the gasoline engine to generate more electricity in order to maintain high motor rpms. In contrast, e:HEV leverages the greater efficiency of the gasoline engine at higher speeds by simply connecting it directly to the wheels, resulting in quiet, fuel-efficient cruising.

■ e:HEV system overview

Traction motor + Generator motor for simplicity + High efficiency

The two-motor hybrid system features both a traction motor and a generator motor. The traction motor is directly connected to the drive shaft and regenerates electricity during deceleration, while the generator motor is directly connected to the engine. The simple system requires no power-dividing mechanism or transmission and avoids the friction loss they cause, directly leveraging the characteristics of the high-efficiency traction motor to deliver power with exceptional smoothness. The direct connection of the traction motor to the engine similarly avoids a loss of energy.

Intelligent use of 3 drive modes
for high efficiency in every situation

EV Drive Mode

When the driver starts off or drives in the city, the system uses only the traction motor to power the vehicle, drawing electricity from the battery. In this mode, the gasoline engine is not running and the vehicle operates as an EV. Based on the driver’s operation of the accelerator pedal, the system precisely controls the power output of the motor for a smooth and responsive driving experience.

Hybrid Drive Mode

The system generates electricity with the gasoline engine and provides power to the wheels via the traction motor. As needed, the system also draws electricity from the battery to deliver powerful acceleration. By optimizing the balance between acceleration Gs in response to driver input and rising engine rpms, the system offers a smooth, linear acceleration feel.

Engine Drive Mode

In high-speed cruising, which requires less torque, it is more efficient to rely exclusively on the engine for power than to operate the motor at high rpm. The system therefore directly connects the engine driveshaft to the wheels to minimize energy loss.

EV Drive Mode (regenerative)

When the vehicle decelerates or travels downhill, the rotating tires turn the traction motor, which generates electricity. In this way, the system converts kinetic energy into electricity, storing it in the battery.