Design

The first generation of the Honda Civic Hybrid was based on the seventh generation Honda Civic. It was the first mainstream vehicle from Honda equipped with a gasoline-electric hybrid system and became the second hybrid model of the company after Insight. Model with manual transmission was rated 46 mpg city / 51 mpg highway according to EPA fuel mileage estimates,^[5] about the same combined mileage as for the Toyota Prius, and became the most fuel-efficient five-passenger sedan ever sold in North America at the time.

An electric motor is sandwiched between the gasoline engine and the transmission, providing up to 13 horsepower. The motor also acts as a generator, to recharge the car's nickel-metal hydride battery located between the rear seat and the trunk, and as a starter motor.
The motor in Civic hybrid is about a quarter-inch thicker than that of the Insight. Through improvements to the magnetic coils of the DC brushless motor, it achieves 30 percent greater assisting and regenerative torque than the previous model without increasing the size.

It generates more torque (46 versus 36 pound-feet) than the motor in Insight. The electricity is stored in a battery consisting of 120 1.2-volt Ni-MH D-cells wired in series. The battery can charge and discharge more rapidly and efficiently though the total capacity is reduced from the Insight's (6.0 versus 6.5 AH). Efficiency of the battery modules is increased, through a reduction in energy losses. The battery is housed with the electrical controller in a package called the Intelligent Power Unit (IPU). The new packaging reduces the size of the system by 50 percent and allowed to place the IMA equipment behind the rear seat in the trunk. The unit weighs only 63 pounds and is one-third smaller than that of the Insight.