I’ve Been Tracking Carbon Dioxide Levels in My Rivian R1T, And What I Found Supports My Theory That Rivian Hasn’t Taken Cabin Air Quality Seriously While in Auto Mode

One Rivian owner set out to measure something most drivers never think twice about, and what he uncovered might just surprise you.

We talk so much about EV range, performance specs, and software updates, but how often do we think about the actual air we’re breathing inside these machines? Turns out, one Rivian R1T owner did, and what he found might point to a gap in how automakers like Rivian approach cabin air quality. So I was scrolling through the “RIVIAN Electric Vehicles Discussion” group on Facebook this morning and came across a post by Benjamin Ponds. Benjamin had been monitoring the CO₂ levels inside his Rivian R1T using two calibrated meters. He discovered that, during typical driving conditions with the HVAC system set to auto mode, CO₂ concentrations inside the cabin would rise. It would often exceed 2,000 ppm within 30 minutes of driving, and when idling in traffic, levels climbed as high as 3,000 ppm. This raised a serious question in his mind: are Rivian’s HVAC engineers truly prioritizing the air we breathe inside these otherwise forward-thinking electric trucks?

Here’s Benjamin’s full post that brought the issue into focus:

“I have been monitoring CO₂ levels inside my R1T while driving and working this past week. I'm using two different meters simultaneously to verify I'm getting fairly accurate readings, and both have recently been recalibrated to ambient air which is typically around 400 ppm. My typical day can include a 45min–2hr trip, then easily 5–8 stops during the day, and then I ride home. I'm testing with the climate on auto mode. In the mornings, the cabin is usually in the 600 ppm range. Driving solo, the meter with the fastest sensor beeps first warning of 1,500 ppm within 25 minutes of driving. With the family, it happens in 15 minutes. At the 30-minute mark, it alerts at the next warning level, with one exception over the last week, of crossing 2,000 ppm even when solo driving.

When sitting in the truck in traffic, making calls, etc. for 20 minutes, it reaches 2,700–2,900 ppm. I've noticed that on auto mode, the truck will occasionally switch to fresh air and the level drops to the 1,300–1,500 ppm range for a few minutes, then climbs back to the low 2,000s. As I sit here now in the truck for 25 minutes, the faster response sensor just alerted 3,000 ppm. Climate is on auto and hasn't been touched other than temperature all day.

These results do not prove but definitely support my hypothesis that Rivian engineers have not taken CO₂ level control seriously, and they need to revamp the HVAC controls to support a human-friendly cabin environment. All medical documentation I've found, common respiratory recommendations, etc. have drowsiness beginning at 1,000 ppm CO₂ for many people, and that's the recommended level to stay under for prolonged periods. Over 2,000 ppm is sometimes associated with dizziness, brain fog, etc. It gets more drastic as the ppm count rises and exposure time rises, obviously. Manually switching climate to fresh air intake makes the CO₂ ppm count drop from 3,000 ppm to under 600 ppm within 5 minutes. So my original observation and frustration post about the climate constantly 'choosing' recirculate being a potential hazard seems to be grounded in logic, truth, backed by real data, and a concern of habitable environments for modern medicine as well.” He even provided a link to support his research of the potential health trade offs.

What Others Are Saying

Benjamin’s post quickly caught attention. I mean after all, it was detailed, well-researched, and backed by real-world testing. One commenter, Mike Shelton, asked an important question: “Have you performed this testing in any other vehicles for comparison?” Benjamin replied with insight:

“My primary point is in both my other vehicles, they will never switch themselves to recirculate on their own like Rivian does. Rivian seems to be highly preferring recirculation over fresh air, possibly to boost A/C performance. I'm not sure why exactly. Every car made will have excess CO₂ levels inside when left on recirculation. I've tested my gasoline cars and you also get the benefit of increasing your CO levels. Also, if you have any kind of exhaust header leak like our Odyssey.”

That comment alone started a discussion around how different automakers approach climate logic and the trade-offs they make between energy efficiency and interior air quality. Another user, Shelton Don Caramelo Stevens, added:

“This is why I love Facebook groups and other forum platforms. I probably never would have even thought about this, but I learned something interesting and useful today. Thank you, seriously.”

Me too Shelton. His point is powerful after all, as online forums like these are exposing aspects of ownership that simply don’t show up on spec sheets or press releases. Real-world use brings out real-world flaws, with some potential safety concerns.

Martin Bogomolni provided some medical context, noting: “The National Collaborating Centre for Environmental Health (NCCEH) considers 7,000 ppm to be the lowest level at which a health effect has been observed in humans, and that was after several weeks of continuous exposure. That's not to say that a level of 2,000 to 3,000 ppm can’t be improved, but at the same time, those are subclinical levels of exposure for most of the population.”

It’s a fair point, and one that offers some balance. But as Benjamin pointed out, the thresholds for symptoms like brain fog and drowsiness can be lower. Plus, the danger isn’t about acute toxicity here, but about decreased alertness and comfort while driving. That’s a big deal in a truck that’s made for road trips and long daily hauls.

Garrett Buckland had a different interpretation: “This sounds like an excellent feature of the Rivian. Having true recirculation without leaks is a sign of proper functioning HVAC that’s set to Recirculate. If you want outside air, open the window or push the button on the screen. Great validation of the air-tightness of the vehicle and build quality of the HVAC.”

But is this a feature, or a flaw? Many Rivian owners likely assume that Auto mode is actively managing air quality, not just temperature. And in other EVs, like Teslas or certain luxury hybrids, the vehicle intelligently toggles between fresh and recirculated air to maintain both comfort and safety.

The Broader Rivian Experience

So while prioritizing range and cabin consistency makes sense, automakers may need to strike a better balance when it comes to recirculation strategies and overall air quality. But that’s not to say Rivian isn’t winning people over, as one R1T driver even shared their unexpected transformation from EV skeptic to loyalist after giving the truck a chance.

Separately, concerns about quality and service delays have surfaced among owners. One Rivian R1T owner revealed how a service appointment dragged on much longer than expected, leading to frustration and a deeper reflection on the brand’s early production hurdles.

A more technical failure involved a Rivian R1S that experienced extensive interior flooding due to a misrouted HVAC drain line, a defect that rendered the vehicle undriveable just weeks after delivery. The story brought to light how even advanced vehicles can fall victim to basic engineering oversights.

And finally, some Rivian customers have faced other kinds of challenges too. An owner was denied the Colorado EV tax credit despite their vehicle meeting the published weight criteria, as another example. This sparked questions about how incentives are applied in practice and whether EV buyers are being left behind by the system.

As for me though, taking account all these different ownership experiences, I think this whole situation shows how the smallest overlooked system can have an impact. You can have all the range, power, and tech in the world, but if your climate control quietly builds up air that makes you tired and less alert behind the wheel, that could prove to be an issue. It's true for any car maker, but especially true in a vehicle that’s marketed for adventure, road trips, and long hauls. 

Key Takeaways:

• Benjamin’s data-backed post suggests that Rivian’s Auto climate control setting may not manage CO₂ levels adequately during normal driving.
• Elevated CO₂ levels can impair cognitive function, cause drowsiness, and go unnoticed until symptoms arise.
• While some argue the levels found are still “safe,” many sources often set much lower thresholds for optimal performance.
• Other Rivian owners have reported quality concerns, reinforcing that reliability and detail-oriented design remain a work in progress. Even with some loaner vehicles having failed while in service.

What Do You Think?

Have you ever experienced fatigue or fogginess during a long drive in your car and didn’t know why? 

And do you think cabin air quality is something automakers should take more seriously in the Auto climate setting in the future? 

I'd love to hear your take in the comments section below.

Aram Krajekian is a young automotive journalist bringing a fresh perspective to his coverage of the evolving automotive landscape. Follow Aram on X and LinkedIn for daily news coverage about cars.

Image Sources: The “RIVIAN Electric Vehicles Discussion” public Facebook group.