Yes, many machines necessarily need a tachometer, because not once I have heard how many people begin to just a huge fuel emission, especially those who have old cars, so it is better to refer to professional materials just as regards the tachometer, study them in detail and make certain conclusions about the tachometer. I have already found such an article; you can also read it here avtotachki.com/avtomobilnyj-tahometr-chto-eto-i-dlya-chego-nuzhen/ ; you can just look at it and study it here. It will be useful for everyone, so be sure to read it, I hope that I can really help with it. It is thanks to the tachometer that I have learned that I have fuel leaks in my car, because for me this is an extremely important element of the car because of this I recently replaced the old tachometer with a new one, so that I can always keep abreast of what happens to my car.