How Car Dashboard Displays Work

By: Molly Edmonds  | 
A car dashboard lit up at night
Your car dashboard is a useful tool.

­"Keep your eyes on the road" is the mantra of every driver's education teacher and nervous passenger, but we really don't keep our eyes on the road at all times. And that's not to say that we're engaging in dangerous behavior like texting or changing radio stations while driving — we're actually briefly averting our eyes to look at the car dashboard.

So, what's taking up that valuable real estate on your car's dashboard?


Car Dashboard Display

A dashboard display showing "empty"
Running on empty?

At a minimum, your dashboard display has a speedometer and a fuel gauge. In addition to those gauges, the display will feature some combination of a tachometer, charging system gauge, oil pressure gauge, and engine temperature gauge. Let's have a quick dashboard confessional that covers what each part does.

The speedometer, one of the most frequently used tools, tells you how fast you're going. Traditionally, this gauge relied upon a cable that connected the speedometer to a gear inside the transmission, but now, electric sensors are used with most dashboard devices. Instrument panels basically have a feed of constantly updated information from around the car.


Your fuel gauge can make the difference between a happy-ending romantic comedy (the fella has enough gas to make it to the church in time to get the girl) or a scary horror movie (a couple runs out of gas near an old abandoned warehouse full of werewolves). If you think your fuel gauge is playing mind games with you, you're right. This gauge deliberately stays on full to three-quarters full for a long time to give you the sense that you're getting good mileage.

More Dashboard Display Features

While the speedometer and fuel gauge are two of the most used features, they're just the beginning. If you drive a stick, for instance, you're probably familiar with the tachometer, which measures revolutions per minute (RPM) in the engine. Knowing this information can help you shift at a time when you'll get maximum fuel economy.

Ever needed a jump when your battery went dead? You might have paid more attention to the charging system gauge or warning light afterward. The amount of electrical current that the charging system provides to your vehicle's battery is monitored by either a voltmeter, which measures the voltage in the charging system, or an ammeter, which measures amperage leaving the battery. When the battery is using too much of its own juice and depleting itself without getting refilled by the charging system, then these gauges or warning lights should alert you to the problem.


While many of us strive to lower our blood pressure, we should never strive to have low oil pressure. The oil pressure gauge measures oil pressure in pounds per square inch, and you're going to have a big problem if that pressure falls in a car. Unless you want to destroy your vehicle, stop the car as soon as possible when this gauge alerts you to a problem; you'll likely be warned via an oil lamp warning light in the dash. Similarly, if your engine gets too hot, you should also get off the road as soon as you can. Your temperature gauge, which measures the temperature of engine coolant, will alert you to a dangerous situation.

There are a host of other warning lights designed to let you know about the status of the car.­ Though there have been some efforts to standardize these lights in all makes and models, they are currently personalized to some extent by car manufacturers. You might see these lights for everything from a reminder that someone's not wearing a seatbelt to a warning that tire pressure is low. For more details about what a certain light is trying to tell you, consult your car's manual.


Car Dashboard Symbols

Navigating the indicators on your car's dashboard can sometimes feel like deciphering an ancient script. Among these, some symbols are more critical than others, directly relating to your vehicle's safety and operational integrity. Here, we delve into the meanings behind a few essential dashboard warning lights.

Engine Warning Light

The engine warning light, often referred to as the check engine light, is a multifaceted symbol representing a range of potential issues, from a loose gas cap to a more severe engine malfunction. Its activation suggests that your vehicle's onboard diagnostics system has detected a problem that could affect the engine's efficiency and emissions.


Tire Pressure Warning Light

Part of the tire pressure monitoring system, this symbol warns you when the pressure in one or more of your tires is too low or too high. Driving with incorrect tire pressure can lead to decreased fuel efficiency, increased tire wear, and even tire failure, posing a significant safety risk.

Oil Pressure Warning Light

This critical indicator illuminates when there's a problem with your car's oil pressure system, signaling that the oil pressure is too low. Low oil pressure can cause severe damage to your engine due to inadequate lubrication, highlighting the urgency of addressing this issue promptly.

Brake Warning Light

The brake warning light alerts you to several potential issues related to your vehicle's braking system. It may indicate that the parking brake is engaged, there's a significant drop in the brake fluid level, or there's a problem with the anti-lock brake system (ABS). Ensuring your brakes are functioning correctly is paramount for safe driving.

Temperature Warning Light

An increase in your engine's temperature beyond the optimal range triggers the temperature warning light. This could signify a malfunction within the cooling system, such as a leak or a failed thermostat, which, if not addressed, could lead to engine overheating and possible engine damage.

Battery Alert Light

When the battery alert light comes on, it indicates issues with your vehicle's electrical charging system. It doesn't necessarily mean the battery itself is failing, but rather that the system charging the battery (like the alternator) might not be functioning correctly, which could lead to a loss of power.

Regular maintenance and prompt attention to these indicators can help ensure your vehicle remains in good working condition, reducing the risk of breakdowns and costly repairs. Always consult your vehicle's owner manual for specific information and guidance related to these dashboard symbols and what steps to take when they illuminate.


Dashboard Display Design

A vintage car dashboard
Miss the good old days? Here's the dashboard display in a vintage car.

First impressions are important, and a dashboard provides your introduction to each automobile you drive. Designers get paid to think about what each person might want from the dashboard, because, unlike with potential partners, you're not likely to ask for a second date with that car if you don't get the information you need upfront. The style, shape, and layout of the dashboard can be a deal-breaker when buying a car.

That's why some drivers may have a completely electronic dashboard display, while others still watch the rise and fall of a needle. Some drivers want as much information as possible about their driving and their car; people with displays that show real-time fuel economy information might make a game out of trying to improve their driving with each mile.


­The need to control additional technology, from power mirrors to a stereo system, means that dashboard displays will only become more diverse in the future. At one point, you may have imagined a future dashboard that included drowsiness sensors, advanced navigation systems, and voice recognition systems that allow you to ask your car questions. This "dashboard of the future" has materialized!

That begs the question, of course, as to when a dashboard display becomes a dashboard distraction. Safety advocacy groups worry that drivers will perceive that most of the driving is being done for them with dashboard gadgets such as self-parking devices, lane-change alerts, and cruise control. They think people will pay less attention to the road and their driving, while even those who are trying to pay attention will be distracted by the constant hum of beeps and the constant flash of notifications from the dashboard. There's a balance between multitasking and keeping those eyes on the road.


Car Dashboards Through the Years

The term "dashboard" didn't originate with traffic jams that made drivers want to dash their heads against something hard in the hopes of losing consciousness but instead was passed down to us from the horse and buggy days. Fans of the song "Jingle Bells" have long known that the proper speed for a one-horse open sleigh was "dashing," but when horses started to dash along o'er the fields, bells on bobtails weren't the only things ringing. The cries of the driver and passenger likely also rang out as they got splattered with mud, meaning that spirits were definitely not bright and laughing all the way wasn't an option. So along came a piece of wood that protected the buggy's passengers from all the mud and slush, which was known as the dashboard.

­When cars replaced carriages, that dashboard came too, as an ordinary slab of wood under the windshield. Dashboard displays, or instrument panels, were a little bit longer in coming. If you needed to know how much gas was left in an early car, you put a stick in your gas tank, and if you wanted to know the temperature, you went to the radiator itself. By the 1930s, though, cars started coming with gauges, and by the mid-30s, all cars included what has been graciously termed the "idiot light" — a warning light indicating that something is wrong with the vehicle. Even in the present day, manufacturers are tinkering with the instrument panel, moving it to the center of the dashboard or packing it full of technology that may make keeping your eyes on the road harder than ever.



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