The Honda's hybrid Civic has an updated version of the IMA hybrid system that was developed for and proven in the Insight. The hybrid Civic also uses a different gasoline engine than is found in the Insight.

Differences in Gasoline Engine

The Civic's gasoline engine incorporates Honda's state-of-the-art i-DSI (direct and sequential ignition) lean-burn combustion technology, along with a newly-developed cylinder idling system. This system adapts Honda's VTEC variable valve control system to significantly increase the amount of electrical energy recovered during deceleration.

The table below summarizes the differences and major similarities between the Insight and Hybrid Civic engines:

Changes to IMA Hybrid System

Honda has made changes to the IMA system for the Civic, to allow for more compact and flexible packaging, and to improve efficiency. The IMA system's capacity has also been increased to match the larger size and weight of the Civic. Here are the details of these improvements:

1. Improvements to the internal magnetic coils of the ultra-thin DC brushless motor, which boasts the world's highest output density and overall efficiency, achieves 30 percent greater assisting and regenerative torque than the previous model, without increasing the size.

2. The inverter and the pre-driver have been combined, reducing the weight of the Power Control Unit (PCU) by around 30 percent, and its volume by around 40 percent in comparison to the present system.

3. The efficiency of the battery modules has been increased, resulting in reduced energy losses. The battery's storage box and peripheral equipment have been made more compact, for an approximate 30 percent reduction in volume.

4. The lighter, more compact, more efficient PCU and battery have been integrated into a single Intelligent Power Unit (IPU) that can be stored behind the rear seat of a passenger sedan.

5. Integrating the IPU allows the two cooling circuits previously used to be combined into one. Total volume of the PCU and battery has been reduced by 50 percent.