Why aren’t digital gauges in cars more prevalent today?

In My Humble Opinion
1

When I was a teen in the 80’s, I remember thinking the all digital instrument panel in the new C4 model Corvettes was just the coolest thing ever. Even some of the mid-level Japanese imports (Nissan comes to mind) had attractive digital gauges. Clearly, it was a sign of future progress.

Present day, nearly every vehicle on the road, from the lowly econobox to my wife’s Lexus, has the same generic analog gauging that’s been around forever. Even with the advent of HUDS and LCD information displays, they persist. Why?

I know some of the early digital technology was of questionable quality and expensive to repair/replace. Nothing could be more frustrating than having an LED burnt out on the speedometer (“really officer, I didn’t realize I was going 77 –my speedo said I was doing 17”), but reliability, durability, and cost have vastly improved to the point that these should be non-issues. Digital gauges could easily be plug & play for that matter. Think of the customization possibilities.

Automakers would probably respond that they are just supplying what the buying public wants, but is that really true? They really don’t offer a choice, do they? I imagine a lot tech-savvy types these days would prefer bright, colorful gauges loaded with information over their simple boring analogs, right? I know I would.

2

Analog vs. digital are good for different purposes. With analog, it’s easy to quickly glance at the display and get a rough idea of what the value is. Digital displays are capable of more precise display of information (e.g., you can see that you’re doing 56 MPH rather than “around 55”), but require more cognitive resources on your part.

When you’re driving, you want to minimize the amount of cognitive resources you spend paying attention to the dashboard (since it’s better to see what’s going on in traffic), so analog displays are generally more appropriate.

Consider the difference between the radio display and the speedometer; the former is generally digital nowadays, but the latter is typically analog. With the radio, it’s important to know exactly what frequency you’re on in order to set the right station, but once you do that you generally don’t need to look at the display very often. In contrast, you look at the speedometer more often, but the exact value isn’t as important. The different requirements lend themselves to different types of displays.

3

At a glance, needles are easier to check than numbers and the less time you are looking at gages, the more time you have to tune the radio and dial the cell phone.

In single pilot airplanes when flying instruments say, You are real busy flying and to check on the engines health is to be done regularly also but quickly. The human eye and brain will notice a needle in a different position quickly and that is what you are looking for, “change” if it is all normal, the needles are in their normal position but if things are changing when they are not supposed to, that needs to get your attention.

Some pilots go so far as to rotate all the instruments so that their normal reading is straight up. Then any deviation is even quicker to be noted.

We had buzzers on our oil pressure when I was flying pipeline patrol because if we saw a loss of oil pressure, we were not doing our job. They were paying us $1.00 an hour, 90¢ to look at the ground and 10¢ to fly the airplane. The fact that we were VERY close to the ground also made it wise to keep our eyes outside the cockpit.

Cars are always close and just inches and seconds from crashing into each other so the faster you can scan necessary instrumentation, the better.

YMMV

4

I have one of the C4 Corvettes that you mention with a LCD display. Although I do like it better than analog, all of the LCDs were damaged by sunlight and had to be replaced (there are 3 LCDS, at about $100 a pop. and most people are not going to replace it themselves which costs another $200.00 or more. ) I suspect this is why they got replaced with analog in the C4, I belive around 1990. They ALWAYS go bad sooner or later and LCDs are big business.

5

OH yeah I almost forgot. The lightbulbs behind the LCD are about $15 EACH, and there are 4 in the corvette LCD.

6

The Toyota Prius has a digital speedometer. I thought I would hate it - took me about a week to get used to it.

Brian

7

My 2003 Suzuki Aerio has a digital dashboard; well, the speedo’s digits, and the tach and gas gauge are bar graphs. I got used to it quickly and have no problems with it.

I know the arguments about being better able to judge the rate of change (acceleration) by watching a needle, but why would you need to know rate of change? Rate of change of engine RPM? Heck, I shift by ear. Rate of change of speed? That’s what scenery is for. Rate of change of gas level? Get outta here.

There is one problem; in bright sunlight the numbers can be washed out. But I’m not sure that in that same sunlight I’d be able to see gauges, either (glare on the glass).

It’s kind of a moot point, anyway, as Suzuki went to conventional gauges on the Aerio in 2005. Incidentally, it’s a great car and you should buy one.

8

My dad had a '66 Toronado which had a different speedometer. Rather than a moving needle, it had a cylinder that rotated around and the needle was a line scribed on the plastic window. He didn’t like it because he had to look at the dial and read the number to determine the speed instead of glancing at the position of the needle to see if he was speeding.

9

My brother also had a Toronado (1967) with the cylinderical speedometer. It was like a drum the rotated under a red line indicating the speed. At rest, you see 0, above it is 5 MPH and below is 135 MPH.

My brother tried to get it to roll around from 135 back to zero but couldn’t get it above 138 before bottoming out on some railroad tracks - I guess seeing the sparks in the rearview mirror convinced him to slow down (it was a low-slug car).

10

The big question to ask is, “What do digital displays do that analog doesn’t do better?”

Analog displays are actually excellent from a human factors standpoint. My speedometer has markings in metric and english. At a glance, I can tell my speed in either one, without having to push a ‘mode’ button or do anything else.

Analog displays are excellent for visibility. As the light gets brighter, they actually get easier to read. At night, they are easy to illuminate.

Analog displays are reliable. In 25 years of driving, I’ve never had a speedometer fail on me.

Analog displays impart a ton of information at a glance. You soon learn that the needle should be about *there for highway travel, and about *there for city travel. At a quick glance, you can then tell whether your speed is about right.

Analog gauges for temperature and pressure and such are great, because the absolute value of these measures rarely matters. What matters if you are ‘in the green’. It also helps to know if you are in the high side of the green, or the low side. But whether the temperature is 300 or 305 is irrelevant in a typical vehicle. My eyes can sweep across the dashboard and instantly tell if all my various readings are good. If instead I have a bunch of digital readouts, it’s much, much harder to figure out exactly what’s going on. For example, if I glance at my instruments and see the temp needle high and the oil pressure needle low, that tells me a lot about what’s happening. But what if I look across and see the temp is 310 and the oil pressure 12psi? I have to do a lot of mental work to gain a ‘picture’ of what’s going on, especially if my numbers fluctuate around a lot.

So for digital gauges to replace analog, they have to offer something analog doesn’t have. There are some things like that. Peak hold, for example. Or fast response. That’s why you see lots of digital VU meters in audio equipment. They respond to transients faster than analog, and they can hold important values that you might miss with an analog needle.

But in a car, there aren’t many uses for that kind of meter. The C4 corvette was an interesting experiment in that it did try to give you new information with the tachometer - the bars were in the shape of the torque curve of the engine, so you could tell at a glance whether you were near the optimum torque. Of course, the problem with that is if you modify the engine or it ages, suddenly the torque curve is misleading.

The other reason to use digital gauges would be cost. In the past, they have been more expensive. But now I’m not so sure, and in the future it will almost certainly be cheaper to simply install a digital panel that replicates a whole bunch of instruments. This is a benefit to manufacturers, but it’s not clear that it will be a benefit to the rest of us.

11

Of course, an digital display can show analog gages with needles if the proper screen is used,

See glass cockpits, a lot of gage representations on them. :wink:

12

I worked with Ford during the 1980s when they were going hot and heavy into digital gauges. They dropped the idea because customers hated them. The #1 thing they hated was the fact that the speedometer showed a speed, and they wanted a dial to show them whether they were speeding up or slowing down. Ditto with temperature and gas gauges.

I’m sure that some people loved the digital gauges, but Ford wasn’t ready to offer one type of dash display as standard and the other as an option.

Oh, and those instant-clearing windshields that defrosted in a matter of seconds? Customers weren’t happy with them after they found out it cost three times as much to replace as a regular windshield.

13

I had a 96 Chevy Blazer with a digital speedometer. It just stopped working one day. After the quote of $2000 to get it fixed, I lived without a speedometer. My father’s C5 Corvette has digital displays, and he likes the HUD, but not the digital speedometer.

I much prefer my analog.

14

I had mine roll on around to 20 mph a few times, but there is no way that the speedometer could have been correct. I believe that the specification was for about 124 mph top speed. (And yes, when running flat out, you could see the gas gage slowly move down.)

The moving numbers were annoying, particularly when they bounced about when speed suddenly changed (very similar to how numbers on a weight scale bounce about when you hop on or off).