The standard vehicle propulsion system and its controls are compared with a flywheel propulsion system. Different concepts of control and various system configurations are explored. Some considerations for the design of a general purpose automatic flywheel transmission vehicle are presented and discussed. Specifications required for a flywheel transmission system which can achieve substantial mileage improvements and provide high performance are presented. The resulting vehicle would have performance of 0–60 mph in less than 10 seconds and achieve 50 miles per gallon on the Federal Urban Driving Cycle (FUDC) at an inertia weight of 3,000 lb. Higher mileages are possible for lighter vehicles. Fuel economy is achieved by (1) engine operation only at minimum BSFC, (2) elimination of engine idle, (3) recovery of energy from braking and (4) minimizing transmission losses.