A motor vehicle’s rev counter, or tachometer, is an invaluable component that assists a driver to protect the vehicle’s engine from the damage that can be caused by excessive work.

A rev counter is one of the instruments that commonly appears on the dashboard panel and can either be displayed as either an analogue design or in digital form. The rev counter works by displaying the optimum time to change gear before over revving. This enhances the peak engine power and torque.

In more modern vehicles the driver receives additional assistance from the rev counter. These more sophisticated versions have warning lights to indicate when it is the best time, in terms of the number of revolutions per minute reached, to change gear.

In addition to protecting the engine mechanism, the rev counter has three important features. Firstly, because it prevents the driver from working the engine too hard it optimises fuel and oil consumption. Secondly, the reduction in fuel and oil consumption saves money on running costs. Finally, because the engine is running at its optimum performance level, exhaust emissions can be reduced.

As part of the armoury of appliances in a modern motor vehicle, the rev counter is one of the most effective in aiding the driver to make the most out of an engine’s performance.