This document summarizes a seminar presentation on Idle Stop Start (I3S) technology. I3S technology automatically shuts off the engine when idling to reduce fuel consumption and emissions. The technology was first developed by Toyota in 1964 and has improved fuel economy by about 10% according to tests. I3S works by using a battery, electric generator, starter, and sensor to restart the engine within 350 milliseconds when needed. I3S reduces fuel consumption by 5-10% in city driving and lowers CO2 emissions by 7-8%. While the technology cuts costs and emissions, it provides only minor fuel savings compared to hybrid systems and some vehicle functions may not work with the engine off. I3S