This study is in Design and construction of car engine tachometer. Car engine tachometer is an electronic device that shows the RPM (Revolution/Minute) of the engine shaft in a car. This device enables the driver to select suitable throttle and gear set for the driving conditions, prolonged use at high speeds can cause insufficient lubrication which will affect the engine. However, this project work combines electrical components of different makeup which was used to design the car engine tachometer. The car engine tachometer is constructed by mounting the components on the Veroboard as shown in the circuit diagram. Car engine tachometer helps one to select a suitable gear. Hence it can be used both manually and in auto-mobile car engines.