Project Title

EV Clutch System

Document Type


Date of Degree Completion

Spring 2020


School Administration

Committee Chair

Sathyanarayanan Rajendran


This project’s goal was to add a clutch system to an electrical vehicle at Central Washington University. The project’s second goal was to have the clutch system improve the electrical vehicle’s fuel economy for Electrathon events. Electrathon uses an equivalent mpg formula to determine an electrical vehicle’s “fuel economy.” Based on the amount of energy in kilo-Watt hours in a gallon of gas, Electrathon assumes each car uses 0.026 gallons of “gas” in the hour long race and the mpg value given to an electrical vehicle is based on the distance the vehicle travels in the race. Analyzes and problem solving showed that only a lightweight clutch system was going to effectively increase the fuel economy of the small electrical vehicle.

A one-way clutch was purchased. Then a hub was manufactured, and the clutch was pressed into the middle of the hub, then screws held the clutch system up against a sprocket on the driven shaft. This clutch system allowed the electric motor to drive the vehicle forward. When power is no longer being delivered from the motor, the clutch system allows the vehicle to “coast” forward. This idea of covering more distance with the same amount of input energy is what makes the addition of a one-way clutch system so useful.

The clutch system proved to add as much as 5 mpg (6% increase) to the electrical vehicle’s fuel economy. In a full speed test, the vehicle coasted 48 more feet on average when the clutch system was equipped.