Don’t check your calendar — it is indeed just past Thanksgiving and not March 32nd. That vehicle above this text is real and if all goes well, you could buy one in 2025. The HW Electro Puzzle is a Kei-sized electric commercial van designed to help you survive disasters all with a face that will make your heart melt. Let’s take a look.

Kei cars, or Keijidōsha, are the smallest class of cars allowed on Japanese roadways. These vehicles have size and engine restrictions. In exchange for dealing with diminutive size and power, owners of these vehicles benefit from tax and insurance benefits. If you want a Kei car in America, most of the time you’ll have to wait until the one you want is 25 years old. You can get newer ones, but those will be low-speed vehicles not legal for highway use. Japan’s HW Electro has not stated what its Puzzle EV van will be classified as in America, but I could see it as a low-speed delivery vehicle.

HW Electro was founded in 2019 in Japan with a mission statement of “We manufacture and sell electric vehicles (mainly light commercial vehicles) that will lead the way in the future, with an excellent concept that takes economic efficiency and environmental issues into account.”

The young company says it is the first company in Japan to obtain a license plate number for imported electric light commercial vehicles, and as of 2019, the company says it is one of three selling electric light commercial vehicles in Japan.

HW Electro is led by CEO Xiao Weicheng, who believes the switch to EVs has taken too long for commercial vehicles. Weicheng believes the best plan forward is to get light electric commercial vehicles on the road as soon as possible. HW Electro entered the Japanese market with the Elemo, a tiny electric cabover cube truck.

That little guy is targeted at businesses needing to navigate urban environments, neighborhoods, and farm roads. The Elemo is built in Hangzhou, China, which seems to explain the previous claim about getting a plate number for an imported electric light commercial vehicle.

HW Electro has also filed for an IPO with the Securities and Exchange Commission. It’s seeking to raise $17.25 million with it. In the filing, the company says that in fiscal years 2022 and 2023, it delivered 66 and 16 electric light commercial vehicles to 15 and 11 customers, respectively. So, the company is building and selling vehicles, albeit not a ton of them at a time.

HW Electro Puzzle

So, what are we getting here in 2025? The Puzzle concept was first shown during the 2023 Japan Mobility Show before it was unveiled again to press in New York. Weicheng says this about the Puzzle:

“The PUZZLE launch marks HW ELECTRO’s dedication to addressing environmental challenges and creating innovative eco-friendly solutions to the commercial vehicle market. We are excited to officially showcase PUZZLE today and we look forward to making it available in the U.S. market in 2025.”

The Puzzle is an all-electric commercial van measuring 11.13 feet long, 4.83 feet wide, and 6.3 feet tall. It rides on cute 15-inch wheels and rides on a 97.63-inch wheelbase. Like any good delivery van, the driver can access their cargo from the sides or from the rear, and the van has a 770-pound payload. Also like many Japanese vehicles, it’s built to help you survive a disaster. This means the van has external AC outlets, USB ports, Wi-Fi internet, some emergency tools, a crowbar, and a first aid kit. It’s basically a rolling power station! Speaking of power, the van’s roof is also covered in photovoltaic panels to help extend the battery’s life.

The design, while cute, is also functional. HW Electro says the friendly body will help the company cut down on tooling and costs. Multiple parts of the body also use the same panels, further simplifying manufacturing.

The interior of the van is pretty minimalist. There are a couple of displays, but they aren’t huge. They are accompanied by a handful of buttons, outlets to plug in gadgets, and a fold-flat passenger seat.

If you didn’t notice, the interior panels have what seems to be pegboard surfaces so you can hang accessories. My favorite part about the interior is the shifter. It almost looks like a glossy reimagining of a Hurst shifter. I dig it.

Weirdly, while HW Electro has released no information about the battery, the motor, the range, or literally anything else, it did release a companion app. This app allows a Puzzle owner to monitor their vehicle’s vitals, location, and other statistics. HW Electro envisions a future where owners will use an app for routing, dispatch, vending, and calling for emergency services.

We’ll be watching this one as 2025 nears. If the Puzzle ends up as a low-speed vehicle, it probably won’t be super useful outside of a city. On the other hand, this does seem like the perfect little van for local deliveries. Either way, it’s as cute as a button and I just want to give it a hug.

(Images: HW Electro)

The post This Adorable Japanese Electric Micro-Van Might Be Coming To America In 2025 And I’m Excited appeared first on The Autopian.

They’ll join the ZeniMax QA union

Continue reading…

If you’ve ever owned an old front-wheel drive car with high mileage, you’ve probably heard the death clicks of a tired CV joint. They’re the special joints that let a driveshaft move and flex as a car’s wheel moves up and down (and, in the case of the front wheels, as it steers). Unfortunately, these take up valuable space, and so does a gearbox, so to get more room for batteries, Hyundai has developed the Universal Wheel Drive System, or Uni Wheel for short. It’s seriously wacky, and we’re left with many questions.

First, we need to talk about what a typical electric vehicle driveline looks like. Generally, there’s an electric motor bolted to a differential, with some power electronics attached somewhere. This whole assembly is usually at or near the axle centerline, and has one axle shaft going from each of the two differential outputs to each driven wheel. Here, you can see Hyundai’s E-GMP platform below:

Look at all that…stuff. Well, Hyundai just dropped a press release on a technology that it hopes will clear out that area so it can be used for other things like batteries. It’s called the Uni Wheel, and it aims to completely change the typical EV drivetrain design.

Fundamentally, it’s a fancy wheel hub with the reduction gear integrated into the hub itself (i.e. no differential/gearbox needed), using a planetary gear configuration. Power from the motor is sent to the sun gear in the center of the hub. The sun gear is connected to two sets of four pinion gears that each transfer drive to the outer ring gear. The wheel is mounted to the ring gear and thus when the ring is driven, the wheel turns. If all of that sounded confusing, here’s a video:

The magic of this setup is the way Hyundai has configured the sun and pinion gears. The two sets of pinion gears are mounted on a pivoting frame, which allows the sun gear to move up and down in the vertical plane relative to the ring gear. This means that the drive motor can be solidly mounted to the vehicle’s chassis with a straight driveshaft going to the sun gear.

As the wheel moves up and down, the pinion gears move around on pivots to maintain drive from the sun gear to the ring gear, but there’s no need for any flexible CV joints in the arrangement, except for on the steering axle. Just as valuable is the fact that the gearing in the hub provides a gear reduction that makes a separate gearbox/differential redundant, freeing up lots of space. Check it out:

To gain the most potential space savings, it makes sense to use a twin set of motors rather than a single one. The twin motors can be moved out closer to each wheel, leaving a space in the middle of the front end that can be repurposed as desired, such as for more cargo space or more batteries. This has the additional benefit of allowing torque vectoring to each wheel by virtue of having two separate motors.

Hyundai also claims a benefit in efficiency.  “A conventional drive system using a regular CV joint suffers from a decrease in efficiency and durability as the angle of drive shaft deflection increases when traveling over bumpy, undulating surfaces,” notes Hyundai’s press release, adding “Uni Wheel can transmit power with almost no change to efficiency regardless of wheel movement, ensuring high durability and ride comfort.”

Again, here’s a typical setup with the Uni Wheel setup below:

Here’s an animation I made:

It’s a nifty drive solution that comes with serious packaging benefits. However, it does come with a certain level of added complexity. There are plenty of gears and moving parts involved, and the complexity is especially increased if two drive motors are used in place of one previously. It’s hard to imagine such a setup being cheaper than a pair of old-fashioned CV joint driveshafts and a single motor.

[Editor’s Note: Are there any noise concerns of all these gears whining? Also, how are you going to keep those gears lubricated? Is it all just an enclosed box with the gears bathed in oil like an old Portal Axle setup? How will you seal it if you’ve got a shaft that’s moving around like that? (Hyundai’s image shows an open system; how are those gears being lubricated?!). Also, how much extra unsprung weight is this going to add to the system? That could cause some handling compromises. 

Then there are other questions related to degrees-of-freedom. Look at the gif above showing the wheel moving up and down, fore and aft. As you can see, Uni Wheel can account for that. But what about if the rear wheel turns or tips? “Why would a rear wheel turn or tip?” you ask? Well, vehicle dynamics engineers build camber and toe change into suspension kinematics; you’ve probably heard that automakers “build understeer into a suspension.” They do that by allowing the rear wheels to change toe as a function of travel; as our suspension engineer Huibert Mees pointed out, there appears to be no way that Hyundai’s Uni Wheel can account for that unless there’s some kind of joint in that motor output shaft.

Huibert talks about this in his article “I’m A Former Tesla Suspension Engineer And I Need To Tell You Why The ‘Double Ball Joint’ Suspension Is So Incredible.” Here’s a quote from that:

One thing that automakers tend to do is build understeer into their suspensions as a way to maximize vehicle safety should you overcook a turn (the front of a car is designed to crash into things; it’s generally considered better to understeer into something than to go sideways and possibly roll over). David Tracy (who edited this article) discussed how Ford does this with the Ford Bronco Raptor’s “roll steer,” but I’ll talk about how automakers do it with front suspension bushing compliance. Put simply, one way to do it is to make it such that, when you’re turning, the lateral loads on the tire deform bushings in a way that promotes the tire steering away from the turn.

So the rear wheels will “steer’ to some degree, and also, camber will change. I don’t see where Uni Wheel has the capability to accommodate that motion. Here’s what Huibert had to say when I asked him:

It looks like the suspension Hyundai uses there is a trailing arm which would work, but nothing eliminates all the toe and camber compliance you would get. The suspension would have to be extremely rigid and uncomfortable or mounted on a subframe along with the motors.

Apparently “the first ever uni wheel test vehicle has passed a rigorous performance requirement test,” so presumably Hyundai has addressed all of this. We’ve reached out and will update this story if we hear back. -DT]. 

Hyundai talks about the design as having great potential to “revolutionise the design of future mobility devices.” Beyond cars, the automaker’s materials note potential applications like robots or other purpose-built vehicles. For now, it states that research is ongoing and that the design will, in the future, be optimized for mass production.

By the looks of things, and with no specific model plans mentioned, it seems like this design might still be a few years away from hitting production vehicles. [Ed Note: I would bet it will never make it to a mass-produced production vehicle. -DT]. If it works out, we could see better frunks on future Hyundai and Kia products with more room for shrimp than ever before. Won’t that be something?

Image credits: Hyundai Motor Group 

Additional reporting by David Tracy

The post Hyundai Is Showing Off Its Space-Saving ‘Uni Wheel’ That Completely Changes An Electric Vehicle’s Drivetrain, But We Have Questions appeared first on The Autopian.

I had the chance to ride in a Waymo self-driving car (yes, an actual self-driving car on public roads) for a week, and I’m convinced that, as flawed as the whole concept is for many reasons: It is the best transportation experience there is on earth, especially for non-enthusiasts. Here’s why.

“Waymo is going on tour across Los Angeles. Starting in October, Waymo is giving Angelenos a 1 week early access ticket to try our fully autonomous ride-hailing service, Waymo One, for FREE in a neighborhood near you,” Waymo announced earlier this year.  “We’ll be popping up in local spots throughout LA to share the magic of Waymo. At pop ups, we’ll be handing out early access tickets to ride (while supplies last) in addition to special tour merch,” Waymo continued in its announcement.

My girlfriend, who’s surprisingly in-the-know when it comes to…pretty much everything in LA, signed us up, and before you know it I was at a popup staring at a Jaguar I-Pace electric SUV covered in cameras and LIDAR sensors:

At the popup event, I received not just a free T-Shirt, but also a ticket that included the access code I needed in order to get one week of  free self-driving goodness on the Waymo app.

The app itself works just like Uber. With the access code inserted, I just plugged in my destination and starting point, hit “request car” and boom: I got an expected time of Waymo arrival:

There were a few instances where arrival time was over 30 minutes, but that’s understandable. I bet each of these sensor-riddled Jaguars cost over a quarter of a million dollars to develop (I pulled that figure out of my arse), so there can only be so many. For the most part, though, the Waymos showed up in a couple of minutes.

They even featured my rotating initials on the roof-mounted display. My camera couldn’t pick up on the initials, presumably because Waymo is using some kind of pulse width modulation for those LEDs, and the camera frame-rate isn’t liking it. But you’ll have to trust me: It says DT right up top, there:

To get in, I had to hit an “unlock” button on the app, then the door handles presented themselves and I jumped in:

I was greeted with this screen on the back of the center console. “Good afternoon, David,” it reads, prompting me to click the “start ride” button.

I hit the button and we were off! I had USB-C chargers right there, bluetooth was available for use from the rear bench (no touching of that front infotainment screen necessary), and I could see what the car was seeing via the small screen just ahead of me on the back of the center console. Notice the rectangles — they represent cars nearby, while those little circles on the right represent pedestrians or dogs:

Here’s a look at how some of my rides went:

The Ride Is Smooth, But I’d Love To Communicate Preference

You’ll see that, as the car makes a few announcements about how riders should use their seatbelts, they should realize they’re being filmed but not audio-recorded, and that there’s a button to push if you need to talk to a support-agent, the vehicle begins the ride — in this case to the T-Mobile store.

“This is a pretty straightforward drive…honestly I should have walked it,” I admit in the video above, noting how nice the Jaguar’s ride is. For the most part, it was uneventful, except there was a stationary USPS truck in the road, and the Waymo knew to alter its path and to slow down:

The car was also able to see every single pedestrian in sight, especially those on crosswalks:

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One thing you, in some instances, give up when you use a self-driving car is the ability to communicate preference. Take this dropoff at the T-Mobile store. If there were a driver in the front seat, I’d have just said “Hey, you can stop here. It’s good enough,” as I valued my time above all else. But the Waymo kept trying to get closer to the curb. I’d have gladly taken a few more steps and dealt with the added risk to save time:

I will note that it was awesome to see on the screen the warning as I opened my door: “Vehicle approaching.” Whew.

Here’s another ride, this time to Panda Express, my new fast-food go-to:

Sometimes The Car Seems To Want To Follow An Overly-Optimized Path

“It comes to a smooth stop,” I say in the beginning of the clip above, while also noticing that the vehicle seems to steer unnecessarily sometimes, as if it’s trying to follow an optimized path that a human driver would just “smooth out” (so to speak). But overall, as optimized and aso conservative as the ride was (it sometimes avoided certain routes for reasons that weren’t obvious), it was incredibly smooth with accelerator pedal and brake inputs — the same cannot be said about all human drivers. But the physical things you experience while in the Waymo are not really what makes the experience so positive.

“The main takeaway… it drives smoothly, it stops smoothly, sometimes it drives in a way that you wouldn’t expect…but the real takeaway isn’t how the ride is…it’s the feeling you get when you’re in a car by yourself versus if you’re with someone you don’t know,” I say. What I mean is that there’s just that tiny bit of tension that you feel when you get into a car piloted by a stranger when you’re in an Uber or Lyft — tension that you don’t have to deal with in a self-driving car. And it’s palpable.

Hopping into a Waymo with my girlfriend, and knowing it’s just us… it’s a whole different vibe than if we’re with a stranger, and I’m a social person who loves meeting new people (and who loves making sure people are employed and that their jobs aren’t taken over by robots). It’s a significant improvement to the overall experience.

How It Handles An Emergency Vehicle

 

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You’ll notice in the video above, the Jaguar pulls to the side of the road due to an emergency vehicle coming towards us but on the other side of the media. I feel the Jag pulled over too far, perhaps unnecessarily, but it wasn’t really an issue. I’d give the performance a B+.

How It Handles A Bus Stopped In The Middle Of The Lane

 

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At one point my girlfriend and I found ourselves stuck behind a stopped bus, not going anywhere. It took a while, but, as you can see in the clip above, the Waymo Jaguar eventually nudged its nose into traffic that was coming from behind, ultimately forcing itself around the bus. It was awesome.

What Have We Learned?

Obviously, the “Waymo Driver”— which is what the company calls its autonomous driving technology — isn’t perfect. It sometimes pulls over in places I wouldn’t as a driver, it doesn’t take my input if I tell it “No don’t worry, you can just drop me off here,” it pulled over a little too far when an emergency vehicle was coming our way on the other side of a median, it did get stuck behind a bus a bit longer than I’d prefer, and it sometimes seems to take an idealized path that involves more turns that necessary.

But overall, the experience is incredible. In fact, I’ll go so far as to assert that it is the best transportation experience on earth for people who don’t love to drive. Just think about it: What other form of transportation will pick you up from wherever you are, let you work or watch TV or read a book while you’re making your way to your destination and listening to your own music on Bluetooth, won’t talk to you at all or bother you in any way, and offers the freedom of destination that only automobiles do.

You get in, you tell it where to go, and you just end up there, with your work done and with a stress-free mind.

There are tons of questions that need to be answered before self-driving cars become the norm — liability related questions, compatibility with emergency services, labor issues (what will happen to the Uber drivers?), logistical issues related to charging and maintenance and storage, and on and on. But from a pure experience standpoint, I think this may be the greatest transportation experience there is. Not the cleanest, to be sure, as it is still individual mobility, and it also doesn’t solve any traffic issues. Nor is it the fanciest, either (a private jet would be nicer), but I think the most convenient, and the one most likely to have the biggest impact on the world, should it ever reach the mainstream.

Our cityscapes could change (folks could work during their commute, so now a 90 minute drive is no big deal — perhaps folks will move away from cities), traffic fatalities could drop, and on and on. I’m sure you’ve all read about the many promises of self-driving cars. I’m not a huge fan of the overall concept, given that I love driving myself and I find that self-driving cars using the public as test-subjects as they develop the tech is a bit…questionable. Plus I’m not convinced that “advancing” for the sake of advancing is a good thing, especially if it takes away lots of jobs. But again, the experience of riding in a functional self-driving car: It’s good. It’s real good.

Though I’m an enthusiast and would prefer my five-speed Holy Grail Jeep Grand Cherokee.

The post I Rode In An Autonomous Car On Public Roads. It Might be The Greatest Transportation Experience On Earth appeared first on The Autopian.

Are you tired of big EVs that weigh as much as a tower block and cost as much as the moon? Yeah, me too. That’s why it’s exciting to hear that the 2024 Fiat 500e weighs just 2,952 pounds. How on earth did Fiat do that? Well, there are some sacrifices made to keep the weight and footprint down, but it isn’t all bad news. In fact, it might just make this little electric car perfect for urbanites at a price they can afford.

For those keeping track, this is the second Fiat 500e sold in America. The first was a compliance car with just 84 miles of range that was a loss leader for then-Fiat Chrysler. I guess if they took a bath on electric Fiats, they’d be able to sell more Hellcats and all that sort of stuff [Ed Note: Actually, all automakers selling vehicles in California were required to sell an EV, so FCA sucked it up and offered the loss-leading 500e. -DT]. Regardless, Reuters reports that then-CEO Sergio Marchionne told people to not buy it, which leaves the old 500e with quite the interesting legacy.

However, the Hellcat is dead, the 500e is reborn, and it really couldn’t have come at a better time for Stellantis. After all, the Chevrolet Bolt is set to temporarily shuffle off this mortal coil when the calendar year ends, the Nissan Leaf is, um, not great, and the current Mini Cooper SE isn’t exactly a range king.

Granted, neither is the Fiat 500e. Promising just 149 miles of range, that’s only 35 miles more than what the current Mini offers. However, when you’re playing in the shallow end of the range pool, every mile counts. Besides, there’s more to an EV than sheer range — it matters how quickly you can juice up the battery pack when on the road. With that in mind, the 42 kWh “Nickel Manganese Cobalt” lithium0ion battery pack in the 2024 Fiat 500e supports CCS DC fast charging at up to 85 kW. That’s not a massive number, but this isn’t a massive battery pack.

Power output isn’t massive either. The front-wheel-drive 500e puts out just 118 horsepower and 162 lb.-ft. of torque. Zero-to-60 mph happens in a claimed 8.5 seconds, but top speed is a fairly low 94 mph. Never mind that most people won’t go any faster than that, the performance figures of the 500e just aren’t giant-slaying like some might expect from an electric car. That’s okay though, as they don’t have to be. Hell, it also seems perfectly fine that the 2024 Fiat 500e sports drum brakes and a twist beam out back. This thing’s all about style and affordability, two things it has in spades.

The old, rear-engined Fiat 500 of the 1950s is a style icon, and the reborn front-wheel-drive car that went off sale a few years ago reinvented it perfectly. However, as many manufacturers will tell you, getting a second retro rebirth right is a tricky thing. Get it right, and you end up with something like the 2007 Mini Cooper. Get it wrong, and you’ll end up with something glued to the showroom floor. Happily, the 2024 Fiat 500e doesn’t mess too much with a good thing, instead refining it just enough to add a little extra modernity.

Compared to the previous car, the new car stays compact but looks a whole lot more expensive. The daytime running lights in the hood that complete a circular light signature imbue the car with a cute yet feisty face, while touches like the recessed door handles, faceted taillights, and frosted tricolore emblems add a dose of class.

To start, the 2024 Fiat 500e will only come in a special RED trim that supports the fight against AIDS, which you can have in any color so long as it’s red, but that includes a ton of kit as standard. I’m talking LED headlights, automatic climate control, wireless phone charging, a 10.25-inch touchscreen infotainment system, a seven-inch digital cluster, alloy wheels, automatic wipers, and all the stuff you’d expect in a posh city car.

Then there’s the design of the interior, a festival of minimalism and painted surfaces that doesn’t totally eschew physical controls. Beneath the touchscreen, a set of buttons allow hotkey access to everything from the climate control to the power door locks, while a volume scroll wheel takes up residence in the center console next to the drive mode selector and electronic parking brake. I’m particularly fond of the truncated center console that allows step-through access to the driver’s seat from the curbside while opening up the cabin. Oh, and the embossed seat fabric covering seats for four in a pinch? Fabulous, in Italian tradition.

So, the 2024 Fiat 500e is cute and should have enough range for urbanites, but what about affordability? Well, this small electric car with all the amenities most people could realistically want stickers for $34,095 including a $1,595 freight charge. Admittedly, that’s not quite as good as the Chevrolet Bolt, but the Chevrolet soon won’t be an option. It’s worth noting that the 500e probably won’t qualify for any tax incentives if you purchase it outright or finance it, but the leasing loophole is still open, so with some clever accounting, it may effectively cost well under $30,000. A brand new EV for sensible money? Sure, why not.

If you live in Canada, things aren’t quite as affordable with a price tag of $39,995 excluding an unspecified freight charge, but due to the lopsided EV pricing landscape up there, the 500e will still be one of the most affordable EVs in Canada when it goes on sale in British Columbia and Quebec early next year.

Oh yeah, expect the 2024 Fiat 500e to go on sale in early 2024 as a 2024 model. While it certainly isn’t looking like the right EV for everyone, those who can live with 149 miles of range and want a stylish little urban runabout are sure to be stoked. With the affordable side of the American EV market soon to be a bit of a wasteland, this might just be what Fiat needs to survive in America.

(Photo credits: Fiat)

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• The Fiat 500e Is Coming Back To America In 2024 And This Time Not As A ‘Compliance Car’

• Fiat Sold Less Than One Car Per Dealership Last Quarter

• This Classic Fiat 500 Just Won The 2023 Detroit Auto Show

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The post The New 2024 Fiat 500e Is An Adorable $34,095 Electric Car With Acceptable Range appeared first on The Autopian.

Car enthusiasts, particularly those that dabble in keeping older, more experienced vehicles alive, all know that feeling. You’re out on the highway, and you smell something oily, or maybe you smell raw fuel. You’re trying to figure out whether or not that’s coming from your little project, or someone else’s. But what if your car stopped you smelling those nasty things entirely? Well, some cars have a special sensor designed to do just that. Today we’re going to learn about how it works, in fine detail. I even cut one open to look inside!

The sensor goes by a lot of different names. Fundamentally, these are sensors that are able to detect the presence of certain gases in the air. However, automakers like to call them different things. SEAT calls it an air quality sensor, while Volvo calls it the Interior Air Quality Sensor because that sounds even better. However, it’s actually a bit of a misnomer, as we’ll find out shortly, because the sensor actually detects gases outside the cabin. BMW, one of the first companies to implement this technology, calls them AUC sensors. This stands for Automatische Umluft Control in German, which translates to automatic recirculation control in English.  Thanks to BMW’s highly descriptive nomenclature, that tips us off as to how these sensors help keep a car smelling fresh inside.

At their heart, these sensors are charged with detecting the presence of certain gases in the air. Typically, they detect carbon monoxide, nitrogen oxides, and hydrocarbons. The former two are typical products of the combustion process, while unburnt fuels or smoky oil vapors would be the prime example of hydrocarbons in the air out on the road. If you’ve ever driven past a badly-running diesel or a car with a nasty oil leak, you’ve probably suffered the hot, unpleasant smell indicative of a vehicle working its way towards the crusher.

The sensor is usually located somewhere in the front of the vehicle under the hood, and is thusly used to control the HVAC system to avoid these nasty gases making their way into the cabin. These sensors are typically only fitted to vehicles with higher-end automatic HVAC control systems. In duly equipped vehicles, the air quality sensor feature is enabled via setting the recirculation control to automatic or just generally putting the HVAC in full auto mode. Then, when the sensor detects something unpleasant outside the car, the HVAC system will automatically shut flaps to enter recirculation mode so the nasty air doesn’t enter the vehicle.

So far, so simple. But this is The Autopian, where we like to dive a little deeper. Thus, I grabbed one of these sensors and cut it open to try to find out what lurks inside. I selected an AUC sensor used on my 2008 BMW 320D, part number 64119240180. According to the plastic housing, the device was manufactured by Paragon AG, a company founded in 1988 which has long specialized in the production of these sensors. BMW was one of the first automakers to fit an air quality sensor to its vehicles, first doing so in 1989.

Taking apart the sensor was no easy feat, as the part designed to survive in the rough and tumble automotive environments. The components inside aren’t just placed inside a plastic housing, they were overmolded with layers of rubbery plastic goop. This serves to protect the internal components from knocks and vibrations, but makes disassembly very difficult for the ardent and curious engineer. In any case, perseverance and a good pair of side-cutters eventually got me a look at what lay inside

In any case, the sensor fundamentally consists of a small sensor element (see below), which lives inside the front of the plastic housing behind the air inlet holes and a simple filter screen. The sensor element is connected to a small electronic printed circuit board, which hosts the components that condition the sensor signal and convert it to something the vehicle’s ECU can readily understand. Depending on the vehicle, Paragon sensors typically communicate with an ECU via PWM signals, LIN bus, or Klimabus connection.

The sensor element itself is what actually measures the concentration of certain gases in the air. Just looking at it won’t tell you how it works, but a great deal of research will. Paragon’s most popular sensors detect carbon monoxide, nitrogen oxides, and various hydrocarbons such as those in automotive fuels using metal oxide sensing elements which have the benefit of being able to detect gases in low concentrations. These sensors are also very responsive, meaning they can pick up the presence of a gas quite quickly. They’re known for their good recovery time, which refers to the sensor’s ability to react in a timely fashion when the concentration of a given gas has decreased.

It all comes down to chemical reactions that happen on the surface of the metal oxide semiconductor sensing element. If you’re confident in your semiconductor science and university-level chemistry, you can dive into the literature, else, enjoy my simplified explanation here.  The metal oxide tends to have oxygen molecules adsorbed, or stuck, on its surface. Those oxygen atoms immobilize electrons in the conduction band in the surface region of the metal oxide. If that sounds too confusing and complex, here’s a simpler explanation: Oxygen on the surface of the sensor locks up some electrons in the metal oxide. This limits the conductivity of the material to a certain baseline level in regular air.

NOTE TO EDITOR: Can we use images from a published research paper? I know some outlets will but I’m not sure on Autopian policy. This diagram sourced from this paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3264469/

When gases come into contact with the sensing element, they react with the trapped oxygen atoms, and change the conductivity of the sensor. Chemists will tell you that so-called “reducing” gases like carbon monoxide will react with the oxygen atoms to become carbon dioxide. This removes the oxygen atoms from the sensor surface, and their removal leads to an increase in conductivity. This is because the oxygen atoms that are taken away are no longer present to keep the electrons immobilized. By contrast, “oxidizing” gases like nitrogen oxides will effectively donate more oxygen atoms to the sensor surface, immobilizing more electrons and reducing conductivity.

Long story short, certain gases that react with the oxygen on the metal oxide sensor either reduce or increase how conductive the sensor element is. High levels of carbon monoxide, nitrogen oxides, or hydrocarbons can thus be determined by the sensor’s conductivity. When the conductivity shifts up or down from the regular baseline point of clean air, it’s clear there’s an elevated level of the relevant gases that react with the sensor.

The electronics on the sensor measure the conductivity of the sensor element, and process this into a value that can be fed to the vehicle’s HVAC control unit. When elevated levels of the pollutant gases are detected, the HVAC unit shuts the flaps to configure the system for recirculating interior air.

In many cases, the onboard electronics on the sensor are also responsible for regulating its temperature. The performance and conductivity of the metal oxide sensor element can change with temperature, which could make it difficult to get reliable results regarding the presence or absence of pollutants in different conditions. To avoid this problem, a small heating element and temperature sensor is typically included as part of the sensor to keep the element in its ideal operating temperature range.

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These metal oxide gas sensors can be made relatively affordably, which has seen their rollout across more and more vehicles in recent years. Further development in this space is continuing, with companies like Paragon rolling out new types of sensor for picking up particulate pollution and other pollutants. Multi-gas sensors with multiple sensing elements are also becoming more common, using different sensor materials to individually quantify the presence of certain gases.

Historically, these sensors have been a fairly obscure feature. However, their use become more relevant in recent years as customers grow concerned about air quality and its impacts on human health. Notably, Polestar has put the feature front and center in the Polestar 2, with an entire air quality analysis feature available on its infotainment screen, featuring particulate and pollutant analysis.

If you’ve been driving a modern car with a high-end HVAC system, maybe you’ve passively noticed that the dodgy trucks and smoke-belching diesels on the roads don’t seem to smell as bad as they used to. Or, perhaps you never noticed anything at all, as there were no nasty smells to ensnare your nostrils. In any case, it’s worth a tip of the hat to the engineers and scientists that developed these affordable air quality sensors that keep our cars smelling fresh.

Image credits: Lewin Day, Metal Oxide Gas Sensors: Sensitivity and Influencing Factors, Wang, Yin, et al. 2010

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