--- title: "How Rivian Fixed the R1T and R1S so It’ll Stop Devouring Tires" date: "2025-07-08" modified: "2025-07-08" authors: - name: "Joel Feder" job_title: "Director of Content and Product" link: "https://www.thedrive.com/authors/joel-feder" url: "https://www.thedrive.com/news/how-rivian-fixed-conserve-mode-so-the-r1t-and-r1s-will-stop-eating-tires" categories: - "News" - "News by Brand" - "Rivian News" tags: - "Electric Vehicle" - "luxury" - "pickup" - "suv/crossover" --- # How Rivian Fixed the R1T and R1S so It’ll Stop Devouring Tires ![2026 Rivian R1S Quad]() *\Rivian\* When [Rivian]() first launched its quad-motor electric R1T pickup, early-adopter owners discovered something unfortunate: [the truck chewed through tires at an alarming rate]() when driven in its eco "Conserve" mode. I'll get into why, but the big news today is that Rivian has reengineered the system in the second-generation [2026 R1T and R1S Quad]() to stop the carnage. For new models, at least. Like with its 360-degree kick turn, there are both mechanical and software changes in the new Quads that made this possible, so the less-murderous Conserve mode isn't coming to existing vehicles via an over-the-air update. But basically, while the old version forces the heavy truck into front-wheel drive, the new system flips the script and operates more like automatic four-wheel drive. First-generation quad-motor R1s utilized four water-cooled motors sourced from Bosch because Rivian's in-house units, known as the Ascent motor, weren't developed yet. The outsourcing of these motors, along with the automaker's original wiring harness containing 17 ECUs, limited the fine motor control Rivian had over the entire system, according to R1 Chief Engineer Luke Lynch. The result was the R1T and R1S completely shut down both rear motors via declutching when put into Conserve Mode. That turned the R1 into a 7,000-pound, FWD tire-eating monster. Not only that, but the driveline was known to make a concerning clunk noise (and feeling) when engaging or disengaging while underway, which I personally experienced while testing the old truck. ![2026 Rivian R1T Quad chassis]() *2026 Rivian R1T chassis. *Rivian** With the second-generation Quad, Rivian's paired its new electrical architecture, which is a zonal design with only 7 ECUs that [debuted in 2025](), with the new in-house designed and developed oil-cooled Ascent motors. Rivian's Director of Product Management and Vehicle Applications Vivek Surya told *The Drive* with Gen 1 the disconnects (of the motors) was not as controllable. This limited the team's ability to balance the triangle of drivability, NVH (noise, vibration, and harshness, refinement (of the clutch in and clutch out), and efficiency. With the second-gen Quad, Rivian's made Conserve Mode smarter, and more like automatic four-wheel drive in a pickup truck. The system won't just shut down the rear motors and declutch. Surya said it now disconnects at highway speeds or 50 mph or above if there isn't a high torque requirement. When more torque response is requested, such as taking off from a stop, highway passing, or other significant increases in speed, the rear motors instantly, and quietly, clutch back online for four-wheel drive. ![2026 Rivian R1S Quad]() **Joel Feder** By programming the system to automatically reengage the rear motors when torque is called upon, the second-generation Quads should theoretically not eat front tires in Conserve Mode. The system is now more efficient and quicker in going on or offline, too. The front motors feature a silicon carbide (SiC) inverter for better efficiency, while the rear motors have a IGBT inverter, which is less efficient. The front motor system is designed for efficiency while the rear is now purposely designed for power delivery. Surya confirmed the reengineered Conserve Mode works the same in the Tri-Motor R1T and R1S launched in 2025 as the new second-gen Quads. But Dual-Motor models don't have a specific Conserve Mode. Rivian's Chief Software Engineer Wassym Bensaid told *The Drive* that Dual-Motor models automatically clutch in and turn off the single rear motor as able in the All Purpose drive mode. Surya noted a key difference between Dual-Motor models and the Quad and Tri is how the system handles drive modes even when the vehicle wakes up. Quad- and Tri-Motor models will remember and default to the drive mode that was last used except Off-Road mode. *Got a tip? Email us at tips@thedrive.com* ## Author Overseeing what you see, read, touch, hear, and interact with from the vast lakes of Minnesota, Joel Feder shapes how The Drive looks and operates as the head of content and product initiatives. On a daily basis, Joel leads the newsroom and editorial staff playing point on both short-term coverage and long-term strategic plans. His mission is to help ensure The Drive shapes the future of automotive media by helping the team execute original reporting, breaking news, and exclusive opportunities. Regarded as an industry insider and recognized by colleagues, fellow journalists, and manufacturers as a point-person and leader in the industry, Joel owns and runs the largest automotive professionals group on Facebook in an effort to serve and help others. Joel serves as a juror for the World Car Awards. In addition, he is the board chair and chair of the governance and nominating committee for Move Forward MN, a local non-profit that helps at-risk youth with barrier-free mental health and housing services. While you’re reading this he’s either on his computer or iPhone chasing the latest news or drafting a story. ### Author social links [Instagram]() [LinkedIn]() [Bluesky]() [Email]()