Virginia Auto Service

Dashboard Gauges 101

There are gauges on your vehicle’s dashboard that let you know how well your vehicle is operating, and offer warnings when something is amiss.

Dashboard Gauges 101

The minimum number of gauges are the speedometer and the fuel gauge. Often, there is also a temperature gauge. Some vehicles will have a tachometer, voltmeter and/or an oil pressure gauge. If your vehicle doesn’t have a temperature gauge, oil pressure gauge, or charging system gauge then there will be a warning light for these functions.

Here is a simple guide explaining the dashboard gauges to help lessen confusion and ensure you keep your vehicle healthy for the long term:

  • Speedometer

This is one of the two most recognizable dashboard gauges. The speedometer measures the speed that your vehicle is traveling in both miles per hour (mph) and kilometers per hour (km/h). The reading it gives is a rather accurate account of the speed in which your vehicle is operating at that precise moment. Speedometers in modern vehicles are measured from an electronic sensor which transfers the wheel rotation rate directly to the speedometer, which will display the reading in mph or km/h on the dashboard. As the driver, you must monitor the speedometer to make sure that you are operating your vehicle close to the speed limit.

  • Fuel Gauge

This is the second of the most recognizable dashboard gauges. The fuel gauge lets the driver know the current amount of fuel that is left in your tank. When your fuel reaches exceptionally low levels, a warning light will appear on the dashboard in the shape of a gas pump to alert the driver that fuel is needed right away. Remember, you should not allow the fuel to reach these low levels on a regular basis. The fuel pump is immersed in the fuel and the gasoline acts as a sort of coolant for the pump. If the fuel gets too low, the pump is exposed to air and runs the risk of overheating- which can lead to fuel pump failure. For this reason, the fuel gauge should be closely monitored. Try not to let the tank fall much below a quarter full.

  • Tachometer

The tachometer computes the speed the engine is rotating when operating. It measures how quickly the engine spins in revolutions per minute (RPM). Dangerous levels are usually indicated in red. If the gauge reaches these levels, the engine is rotating at such a high velocity that it can cause vehicle complications. Typically, the higher the RPM reading, the higher the rate of fuel consumption and power the engine is putting out. When in lower, consistent RPM levels, the engine is operating at its optimal level which improves fuel mileage. You should monitor the tachometer to make sure you are achieving optimal power output and fuel economy.

  • Temperature Gauge/Lamp

On some vehicle’s there will be a temperature gauge, on others, there will be a warning light in the shape of a thermometer that indicates the engine is reaching a dangerously high temperature. The gauge measures the temperature of the engine coolant. If the gauge reaches red levels, or the warning light comes on, then the coolant temperature is too high. Continuing to operate the vehicle under these conditions can cause extensive damage to the engine. Stop the car immediately to try and cool the engine. Have the engine serviced as soon as possible.

  • Oil Pressure Gauge/Lamp

The oil pressure gauge usually appears in older vehicles. Most newer model vehicles will just have an oil warning lamp to warn the driver that the oil level is low. Having the proper amount of oil is vital to the performance of your engine. Oil is pushed throughout the engine to lubricate the necessary components and keep your vehicle operating properly. When there is not enough oil, it can result in engine failure. This gauge measures the oil pressure in pounds per square inch (PSI). If the gauge reaches levels that are severely low, or the oil lamp appears on the dash, you will need to have your vehicle brought in for an oil service.

  • Charging System Gauge/Lamp

Without the charging system, your vehicle’s battery will drain and your vehicle will stop working. The charging system gauge or warning lamp is responsible for monitoring the health of this system so that the driver is warned of a potential problem before they get stuck. Unlike the oil pressure and coolant temperature gauges, when a problem is indicated, you can continue to drive without causing engine damage. However, you may still end up stuck on the side of the road. To monitor the charging system, two gauges are used- an ammeter to measure amperage going out of, or coming into the battery and a voltmeter to measure the system’s voltage.

We hope you find this quick guide to dashboard gauges helpful.  For high-quality auto repair services, give the experts at Virginia Auto Service a try. Call (602) 266-0200 or schedule an appointment online today for quality care and information to help keep your vehicle performing at its best.