Why Car Mirrors Are Better Than Car Cameras

Walking around the Frankfurt Motor Show on the weekend, there were Audi E-tron shuttles zooming around to ferry attendees between the press room and the far reaches of the show. Like many E-trons in the European market, these ones had the camera-based mirrors that automakers have been putting on concept cars for the past 15 years. And despite usually being a sucker for tech gimmicks, I still don’t get this one.

Even after reading my colleague Justin Westbrook’s piece on the system, I can’t say I’m convinced that this is a good application of cameras.

To be sure, there are advantages to cameras over traditional mirrors. Many new GM products and the new Land Rover Defender, for instance, let you swap between a regular and digital version of the rear-view mirror. The digital version offers a wider field of view and isn’t obstructed by cargo, but the traditional mirror works better at night or for keeping an eye on kids in the back.

That’s a feature I love, in large part because the quick toggle switch means that it’s easy to use a conventional mirror when you need it. And because traditional rear-view central mirrors are always obscured at least partially by the car’s bodywork, it makes sense.

Side view cameras also make a lot of sense. Blind spots are dumb and having to look over your shoulder isn’t convenient. While blind-spot monitors exist, they require a lot of trust that the system is going to pick up cars reliably.

Honda’s lane watch system tried to fix this with a blinker-activated camera, but it only worked for the right side of the car and took over your central screen. The implementation was messy. Now, Hyundai and Kia offer a fantastic system that automatically shows you a camera feed in your instrument cluster when you turn on your turn signals. You still have your mirrors, but the camera pops up right in your line of sight as an extra safety precaution.

That is not how the system works in the Audi E-tron. In markets where it’s legal, the E-tron has no traditional mirrors mounted on the cars doors. Instead, right below where you’d normally find your mirror, there’s a little display inside the car showing the feed from your door-mounted cameras.

So while you still need to look over to the other side of the car to make a rightward lane change, you now have to focus your eyes on a screen. I’m sure it works fine, but there are a few reasons that this seems pointless.

First, if you have to look over anyway, why not use a traditional mirror? Sure the camera offers a wider field of view, but that also means it distorts your perspective. Convex mirrors inside the larger mirror solved this problem for a few bucks 20 years ago, so adding a complicated camera system with a price tag exceeding $2000 strikes me as a solution in search of a problem.

Warped perspectives also make it significantly harder to line up the car when parking or manoeuvring. I love using a backup camera to judge distances and confirm that my path is clear, but for lining up my angle around the tight bend in my driveway, there’s nothing better than a traditional mirror with its fixed perspective.

I’ve had to do that turn in a Gladiator without doors and, therefore, without mirrors. It’s not fun. You don’t realise how often you use your door mirrors until you don’t have them.

Which brings me to another problem. With an electronic screen, a high-def camera and a computer processing the image, there are three points of failure. Should any of them have a problem that requires a reboot or blacks out the screen — which even the best infotainment screens do sometimes — you’re now driving without mirrors.

Plus, snow, rain and dirt tend to blot out huge sections of cameras in situations where my mirrors remain totally usable. Audi’s camera setup is more protected, but water and dirt will still sometimes obscure your view.

So you increase the cost of the car, you don’t make actually looking at your side view any easier than a traditional mirror, you add in failure points and you warp the perspective to make manoeuvring more difficult. None of these things are impossible to live with, but it seems like a lot of trade-offs for essentially two benefits.

One is the wider perspective, which you could already do with a convex mirror or a camera that supplements the mirror and two is the reduced aerodynamic drag.

Especially in an electric vehicle, that’s a win for efficiency. You’ll also see less vibration and noise generated from the wind hitting a smaller camera fairing compared to a larger mirror. The result is a drag coefficient reduction from 0.28 to 0.27, which could give you up to 6.5 more kilometres in ideal conditions.

Any range improvement is welcome, but ultimately it strikes me as a bad compromise. If you’re willing to pay $2000+ for a tiny drag improvement in perfect conditions, while accepting more complexity and failure points, that’s great. For most people though, it’s hard to imagine why you’d bother.

This story originally appeared on Jalopnik.


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