What does the tachometer gauge tell you on the dash?
One of the most important gauges to keep your eye on when you’re driving, the tachometer shows you how fast the engine is turning. Engine speed is measured in revolutions per minute (RPM). The gauge runs from 0 to 7 (x 1000). If the engine is off, then the gauge sits at the 0 mark. During idling, it should move up slightly.
As you press the gas pedal, the tachometer needle will move up the gauge, although it will drop with each transmission shift. However, if the needle edges into the red section of the gauge, that’s your signal to slow down (or that something’s wrong, such as your transmission not shifting correctly). Driving for any length of time with the needle in the red is not recommended, as it could seriously damage the engine.