How Does a Car’s HUD Work?


May 19th, 2020

How Does a Car’s HUD Work?

I think it's safe to say that car displays haven't changed all that much in a very long time. No matter how modern a car may be, all essential driving information can be found at the car instrument panel. The speedometer shows you how fast you're going, the tachometer your engine's RPM, and the fuel gauge shows you how much fuel you've got. Then there are the dozen or so warning lights, as well. Instead of analogue gauges in older models, modern cars will have these devices and indicators displayed digitally. In any case, you have the usual meters all located in the same spot.

While this configuration hasn't changed much, there is one alternative method to display all the same driving information. This is known as a 'heads up display' or 'HUD'. Historically, HUDs were commonly used by fighter pilots. Instead of looking down at their instrument panel, they could see everything they needed to see through their helmets while their heads were in the up position (hence the name). The information would be displayed on their visors right in front of their eyes.

This technology is also available for cars. Automotive heads-up displays (HUDs) make it so that you can see all the vital driving information right on your windscreen.

But you might ask, "So what?"

What's the Point of a HUD?

That's a valid question. What's the point of a higher digital display when you've already got all your meters and gauges doing the same thing? The answer is simple: it's all about your eyes.

When driving (or flying a fighter jet), the most important thing for the driver to do is to keep their eyes on the road in front of them. This 'eyes on the road' idea is crucial so that you can spot and avoid dangers in time, thereby keeping you safe.

If we were to rely only on the gauges on the instrument panel, our vision and attention would be slightly divided between the road and the instrument panel. With a HUD, you could keep your eyes on the road the entire time, keeping yourself informed while paying maximum attention to any dangers ahead.

As an added benefit, HUDs for cars also give you a chance to customise what you see on display. That way, you can choose which driving information you'd like to see the most.

How Does an Automotive HUD Work?

Car drivers don't wear helmets as fighter pilots do. So, there are two basic methods for displaying the information as a HUD. 

The most common way is by reflecting light onto the windscreen or a transparent panel. Using this method, you could set up a HUD just by using your smartphone and a HUD app. Placing your phone on your dashboard, you should see the reflection on your windscreen showing your navigation, speed, and more.

Alternatively, you could also buy a dedicated HUD device. Usually, these devices will have a small transparent display, onto which all your driving information will be reflected. This, too, will be placed on your dashboard in front of the driver's position. 

Another option for using a HUD while driving is to buy smart glasses. Almost like a fighter pilot's helmet, you'll wear the smart glasses and see all of your driving and navigation information through it. This, of course, might cost a little bit more than the other options.

Some newer car models come with heads-up displays included. Even if your car doesn't have one, there are plenty of aftermarket brands offering independent HUDs for automobiles.

Pros and Cons

Having a HUD in your car isn't all positive, though. Even though the HUD encourages you to keep your eyes on the road, it can still end up as a massive distraction. As HUDs become more advanced, you'll probably be able to see more and more information on your windshield. That could lead to the info distracting you too much, to the point that you won't be able to react to dangers on the road quickly enough. 

Automotive HUDs, yay or nay?

If you asked me whether HUDs were a good idea or not, I'd say that neither answer is perfect. The fact of the matter is that HUDs are already widely available. More and more carmakers are including them as a standard feature in cars, and there's no shortage of aftermarket brands making them as well. 

The bottom line is that it comes down to the individual driver. If you choose to get a HUD for your car, be sure that it doesn't end up being a distraction. Be minimal when using whatever customisation options you may have with the HUD you buy.

That way, you'll get to enjoy the benefits of having a HUD but without overloading yourself with information while driving.

If you’re looking for a HUD for your car or other aftermarket car parts and accessories, make sure you buy from reputable sellers. One perfect way to do this while complying with contactless measures at the same time, is to use online car part platforms like 

Through this channel, you can send a request for the part that you need. Instead of you calling multiple sellers and wreckers, CarPart will contact its more than 500 members for you. You will then receive several quotations, from which you may choose the best offer. Using this platform shortens the process of finding a part, and gives you access to the most competitive price and quality in the market. And before we forget, our Request a Part feature is free to use. You’re also under NO OBLIGATION to buy if you don’t like the offers you get. So don’t waste any more time - request a part now

By Ray Hasbollah