A mechanical oil pressure gauge is a device used to measure the flow of engine oil through your car’s engine. Mechanical gauges are different to electrical gauges because they show the flow on an analogue scale determined by taking a tap of the oil flowing around the engine up to the dashboard so you see a real representation of the pressure. This is different to an electrical oil pressure gauge, which measures the flow by the resistance across the oil flowing past.
Oil pressure is essential to the safe and efficient working of your engine. Without sufficient pressure the engine oil is not able to provide lubrication to the Pistons and the bearings and other moving parts in the engine. These parts are trying to press against the cylinder walls or the camshaft and if the oil were not pressurized it would be squeezed out of the way. The pressure provides resistance allowing the oil to act as a cushion between parts so they do not touch.
It is often thought the mechanical gauges are more accurate. They can be purchased in a variety of styles but a black face with red needle is usually the most common. The good news is a replacement gauge is not very expensive, you will be able to purchase one for less than $20. However if you want to fit one to your car and it doesn’t presently have what it can be a tricky job. If you are going to fit a new one it is a good idea to change the engine oil at the same time. Changing your own engine oil is a good way to save money on this expense, far better to save money by doing the work yourself and get a cheap oil change by choosing an inferior oil product.