What are the differences between Honda's second-generation and third-generation hybrid systems?

[Emilia]

The main difference between the third-generation and second-generation systems is the adoption of a more thermally efficient Atkinson engine. The specific details are as follows: 1. Honda's i-MMD hybrid system features three different driving modes: Pure Electric Drive Mode (EV-Drive-Mode), Hybrid Drive Mode (Hybrid-Drive-Mode), and Engine Drive Mode (Engine-Drive-Mode). It switches between these modes based on different driving conditions to achieve optimal performance. 2. There are no structural or operational changes between the third-generation i-MMD system and the second-generation i-MMD system. Both still use a 2.0L Atkinson cycle engine, dual electric motors, and a lithium-ion battery pack. However, in the third-generation i-MMD system, Honda optimized the 2.0L Atkinson cycle engine, increasing its thermal efficiency to 40.6%, higher than the previous generation Accord Hybrid's 38.9%. Additionally, the power unit (IPU) is 32% smaller in volume compared to the previous generation Accord Hybrid, and it also utilizes Honda's newly developed rare-earth-free magnet motors.