📅 2026-May-07 ⬩ ✍️ Ashwin Nanjappa ⬩ 🏷️ linkblog ⬩ 📚 Archive
Great explainer on how hybrid cars work.
Non-hybrid gas engines use the Otto cycle. They are relatively inefficient because they waste energy at the end of the power stroke when hot gases still have pressure that could be captured.
Hybrid gas engines are inspired by the Atkinson cycle. Their power stroke is longer relative to the compression stroke, resulting in much higher efficiency.
The hybrid engines are efficient only at a steady state speed, so it is supported by an electric motor (and small battery) during acceleration or when more torque is needed.
Hybrid’s simpler transmission uses a planetary gear set to drive a pair of motor-generators (MG), where MG1 assists in torque and battery charging and MG2 drives the front wheels.