The Digital Dashboard

Analog vs. Digital

VinylRecordAlbumThe big difference between analog and digital is continuous vs. discrete. An analog signal is a continuous signal in which something like a pointer moves the same way as something else. For example, an analog multimeter has a dial that moves in proportion to the voltage it is measuring.

Those of you of a certain age may remember these odd looking flat black vinyl things called ‘records’. Records are analog devices. A groove is cut into the vinyl. A stylus rides along the groove and translates the wiggles in the groove into an electrical signal, which is then transmitted to a speaker, which turns it into a vibration (which, when pleasant, we call “music”.)

Digital files (your mp3s, for example; everything on your iPod) encode music in 0s and 1s. Instead of a continuous, physical groove, it’s a bunch of data. There are a lot of advantages to digital. It doesn’t degrade with repeated playings, it’s much less fragile, and you can include a lot more information compared to a record player.

On the other hand, digital music can loose some of the ‘character’ of analog music and you cannot substitute a mp3 file for a frisbee.

Like music, the gauges on a car may also be analog or digital. Up until now, NASCAR hasn’t allowed digital gauges. Here’s examples of all three:


On the left is an analog gauge. This is the usual dial gauge that many cars still have. Like the record and the needle, physical components move in response to the car’s speed. (How Stuff Works has a nice explanation of how speedometers work.)

In the middle is an analog gauge that’s been supplemented with LED lights. This was the big deal change a few years ago. The driver didn’t have to squint and try to read the divisions of the gauge. The mechanics would pre-set the gauge so that a few lights would display when the car reaches a particular rpm. The really fancy gauges even had different colored LEDs so that the driver not only had the lights turning on, but the colors to warn them.

A Brief Digression about LEDs

The LED-modified gauge didn’t work its way into racing until the last five to seven years. There’s a good reason why. LEDs are a pretty new innovation. Yes, now you can buy LED lights that change colors and change their colors using your phone.

The principle behind Light Emitting Diodes (LEDs) was discovered in the 1920s, but the first practical LEDs didn’t show up until the 1960s. The first LEDs (circa 1962) were red and so low brightness they were difficult to see. Remember the first calculators?


They had to add plastic, prismatic lenses to make them easier to read because they were hard to read by themselves. They just weren’t bright enough. It wasn’t until the 1970s that high-brightness, affordable LEDs were being made and the spectrum of colors ranged from red to… orange-yellow.

As you move through the rainbow, the wavelength of the light changes. Red is somewhere around 700 nanometers and violet around 400 nanometers. We figured out how to make longer-wavelength LEDs first from a semiconductor material called Gallium Arsenide Phosphide. High-brightness blue LEDs were not invented until 1994 and utilized a different semiconductor called Indium Gallium Nitride. This led to the development of white-light LEDs (you use phosphors to convert blue to red. yellow and green). White light is the combination of all colors and that’s why you can now go and buy a LED lightbulb. The reason we didn’t have LED gauges until recently is that the LEDs needed to be bright and robust enough to survive being a racecar. But those gauges are about to become history. NASCAR will allow digital gauges.

Back to the Digital Tachometer

A digital tachometer gives you numbers directly.  No more trying to read the tiny little divisions on an analog gauge to see how close you can get to your pit road cut off without going over. Whereas an analog tach may tell you you’re somewhere between 4000 rpm and 4100 rpm, the digital tach will tell you you’re at 4036 rpm. Most of the time, that type of precision isn’t good for anything — but when you’re on pit road and trying to stick below the pit road speed limit, you want to know EXACTLY how fast the engine is going.

Actually, you want to know how fast the car is going. Any gauge can be digital – oil pressure, speed, fuel pressure… pretty much any gauge can be made digital.

A digital gauge MAY include a graphical display of some type – sometimes, even ones that look like the familiar analog dials.

The Glass Cockpit

Brian France mentioned the idea of the “glass cockpit” back in July 2012. There’s a continuing fight within NASCAR about how much information drivers and crews should have – and how much of that information ought to be accessible to fans. It seems sort of silly that people are losing races because they got a pit road penalty for speeding. It’s frustrating for everyone involved.

Moving to fuel injection necessitated adding a number of sensors to the cars and integrating them into a single . Digital dashboards were tested back in April at Kentucky, but we’ve heard very little about them since them.

The term “glass cockpit” comes to us from aviation. By the 1970s, the average plane had over 100 gauges and dials. If you need a piece of information – the status of a wing flap, or your fuel level – you don’t want to have to search for it. It needs to be right there, at hand. A racecar isn’t as complicated as an airplane, but the amount of information the driver has access to is getting larger and larger.

Here’s an example of an early-2000’s era dashboard.


Recently, we’ve added a trackbar adjustment knob, too. It’s a lot to look at when you’re going 180 mph.

Here’s a helmet-cam picture from Kevin Harvick’s car. I included it because you’ll notice that the driver is looking through the steering wheel. If you go to the original video (, you can see that the gauges on the sides disappear from view when turning.


Not only can you not see all the information that’s there…  there’s a lot of information that’s not there. There’s no speedometer (I’ve explained that a tachometer is actually more accurate than a speedometer, but when you go to digital, that’s out the window.) There’s no lap time displayed, or cockpit temperature or fuel gauge or tire pressure or…

As NASCAR moves more and more toward technology, the drivers (and crews) will have more and more information available. This is good… up to a point.

How many times have you fumbled around all the menus on a piece of software looking for that command you know is there, but you never remember where it is?

When I’m coming down Pit Road for a pit stop, I don’t care about my lap time or my oil pressure or my fuel pressure. I care about one thing: Don’t speed. And this is one of the big reasons for the digital dash.

Information can be grouped into pages, displaying only the information that is relevant to the driver at that time.

Jamie McMurray tweeted a couple pictures of the digital dashboard during a tire test in Kentucky.

NASCAR_DigitalDash_McMurray2 NASCAR_DigitalDash_McMurray

Important note – it’s the same display in both pictures, just different pages.

A couple interesting things to note:

You can display information in different formats. Your driver is used to gauges? Sure. Note that in the upper picture, there is a red line, a green line and a yellow line right on the tach. A visual indicator for the driver when he or she is getting close to pit road speed or the engine speed at which the engine designers start to get nervous.

The lower display shows lap times! Right now, the driver depends on the spotter or crew chief for that information. And, of course, if you have a driver who doesn’t want to know, you just don’t put that piece of information on the screen.

It looks like the McLaren PCU-500N Digital Dash Display will be the only one allowed for competition. McLaren already makes a display unit (the PCU-8D) for F1. You can get an idea of the types of information they display in the video below.


Optional Now… Mandatory for 2016

ChadKnausAccording to the NASCAR Sprint Cup Series rule book, digital dashboard display

“may be used at all Events after August 5, 2015. Digital dash display use will not be permitted before August 5, 2015. Effective January 1, 2016, a digital dash display must be used at all Events.”

Why August 5th?  Some of the conspiracy theorists over on Reddit suggest that the significance of the date is that it’s Chad Knaus’ birthday.

It’s also Alan Gustafson’s birthday, but Gustafson won’t be using the dashboard in Jeff Gordon’s car this weekend. Why?

As Gustafson said on SiriusXM Radio’s The Morning Drive, the digital dash is about 5 pounds heavier than the analog dash they’re using now. The advantages of the digital dash don’t outweigh (literally) its weight penalty. Five pounds located up high in the car, is a pretty stout competitive disadvantage – until 2016, when everyone is required to run the new dashes.

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About Diandra 455 Articles
I'm a recovering academic who writes about the intersection of science and life. I'm interested in AI, advanced prosthetics, robots and anything that goes fast. Author, THE PHYSICS OF NASCAR and Editor, BIOMEDICAL APPLICATIONS OF NANOTECHNOLOGY

1 Comment

  1. Thank you Diandra. The technical aspects of NASCAR have always been of more interest to me than simply going fast and turning left, or as will be done this weekend, turning right, up the hill, down the hill, etc. Regarding the added weight of the digital board, Bootie Barker always says, “Low and left” when choosing weight optimums. Your previous blog regarding aerodynamics also was fascinating.

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