Ever thought about the gauges on your car’s dash?

Probably the first time you entered a car, the car’s gauges fascinated you and logically you could easily understand what they meant. The minimum number of gauges on a passenger car dashboard is the speedometer and the fuel gauge. The most common additional gauge is the temperature gauge, followed by the tachometer (usually the size of the speedometer), a voltmeter and oil pressure gauge.

If your car does not have, say, a temperature gauge, you will have a warning light for this function but you need to get out of the 70s.

In the past, the most used gauge was the speedometer. A cable that spins inside a flexible tube usually drove the speedometer. The cable is connected on one side to the speedometer and on the other to the speedometer gear inside the transmission.

Today, just about all vehicles have eliminated the cable and use an electronic sensor to measure wheel speed and send the signal to an electronically driven speedometer. The accuracy of the speedometer can be affected by the size of the tyres. If the tyres are larger in diameter than original equipment, the speedometer will read that you are going slower then you actually are.
cSometimes, I believe the fuel gauge is deliberately designed to be inaccurate. After you fill up the tank, the gauge will stay on full for a long time and slowly drop until it reads 3/4 full. After that, it moves progressively faster until the last quarter of a tank seems to go very quickly. When the needle drops below E, there is usually one or two litres left in reserve, so girls, don’t get too worried when the fuel warning light goes on.

To find out for sure, look up your car’s specs and find out how many litres of fuel your tank holds, then the next time you fill up an empty tank, check how many litres it took to fill it.

The difference is your reserve. It is not a good idea to let your tank drop below 1/4. This is because your fuel pump is submerged in fuel at the bottom of the tank. The liquid fuel helps to keep the fuel pump cool. If the fuel level goes too low and uncovers the pump, the pump will run hotter than normal. If you do this often enough, it can shorten the life of the fuel pump and eventually cause it to fail.

The temperature gauge measures the temperature of the engine coolant. When you first start the car, the gauge will read cold. Most temperature gauges do not show temperature numbers, instead they will read cold, hot, and have a normal range, which is usually half way. It is very important to monitor the temperature gauge to be sure that your engine is not overheating.

If you notice that the gauge is reading much hotter than it usually is and the outside temperature is not unusually hot, have the cooling system checked as soon as possible. If the temperature gauge moves all the way to hot, or if the temperature warning light comes on, the engine is overheating. Safely pull off the road and turn the engine off and let it cool. Usually it’s because of a leakage in the cooling system. An overheating engine can quickly cause serious damage.

The tachometer (that thing usually next to the speedometer), also known as revolution-counter, measures how fast the engine is turning in RPM (Revolutions Per Minute). This information is useful if your car has manual transmission and you want to shift at the optimum RPM for best fuel economy or best acceleration.
It is one of the least used gauges on a car with an automatic transmission and as a matter of fact, I honestly think it’s useless.

You should never race your engine so fast that the gauge moves into the red zone as this can cause engine damage; nonetheless, most engines are protected by the engine computer from going into the red zone. Usually, the tachometer shows single digit markings like 1, 2, 3 etc. Somewhere, you will also see an indicator that says RPM x 1000. This means that you multiply the reading by 1000 to get the actual RPM, so if the needle is pointing to 2, the engine is running at 2000 RPM.

Those are the basic dials you’re bound to find on a car. And as much as these are very easy to understand, think of them as an ECG machine (that machine that shows heart pulses in hospitals in movies) for your car.