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Tesla Model S Drive Unit Replacement by the Numbers
During my early days of researching the Tesla Model S, I had concerns about a number of things that were emerging in the press. Fires, Model S drive unit issues, and handling in the snow. Tesla quickly addressed the “firegate” issue by retrofitting the Model S with a titanium shield. My concerns around winter driving, in particular handling in the snow, also became a non-issue after watching several winter driving videos put together by Bjørn Nyland.
Within no time, I became a new Model S owner and quickly learned that driving in the winter could actually be quite fun with a good set of winter tires. Tesla later introduced the all-wheel drive “D” models putting to rest any remaining doubt that the Model S could be the best and safest handling car in the world.
But one question still remains for me, Has Tesla dealt with the Drive Unit issues?
Model S Drive Unit Replacement by the Numbers
There is a group of Model S owners across the forums, but also validated by major publications such as Edmunds, that have had one or more drive unit replacements.
Early reports of drive unit issues ranged from total failures that left the Model S inoperable, to more recent complaints of clunking and milling noises. Elon has said in the past that many of these pre-emptive drive unit replacements were unnecessary and a simple $0.50 shim was all that was really needed, yet Tesla Service centers have been proactively replacing drive units.
The following polls from TMC show that a majority of Model S owners have had their drive units replaced.
While the poll only represents a small sample of Model S owners, one might draw significance in the numbers as the density circles around owners needing a drive unit replacement at relatively low mileage, and without any harsh driving prior to failure.
The polls also give insight to the motive behind each drive unit replacement.
Though it appears the issues mainly center around earlier versions of the Model S, there’s been reports of newer Model S with Autopilot hardware hearing milling noises coming from the drive unit. One viewer described the sound as “sawing wood”.
Tesla’s Response to Drive Unit Issues
In typical Tesla fashion, the company acted fast to address the issues, and curb concerns by offering an unlimited mile/8 year warranty on the drive unit. I think this was a great response by Tesla which put to rest any concerns about the quality and long term durability of their drive units.
Elon is now talking about building a power train that will last a million miles and I believe Tesla continues to put significant energy into improving the drive units. Tesla continues to honor the warranty and is proactively replacing drive units that show early signs of problems.
My Experience
After 12 months of Model S ownership and 30k miles drive, I started hearing a humming noise from the rear of my Model S during highway cruising. The noise was unusual as I had gotten used to hearing only the noise of the tires and wind, but there was a new noise only noticeable when cruising or decelerating with regeneration at 65 MPH and over. The noise continued to become more audible over the next few months, but I learned to live with it and did not contact Tesla. My personal rule of thumb on noise related issues is to wait for passengers to comment on it first. It’s my self crazy check.
Two months after the original drive unit humming noises began, a higher pitched milling type noise started occuring when traveling at speeds of 20 MPH or less. The sound varied depending on how much power was being used. That’s when I reached out to Tesla.
Tesla service record
Tesla service had me come in for a test drive which they can do on demand without you needing to wait. We drove about a block before the Tesla service technician said the drive unit needed to be replaced.
The explanation was that tolerances inside the drive unit have led to metal particles getting into the fluid around the drive unit, and as the concentration of particles increased, it caused the noise from the drive unit to become louder when under load. The new drive units evidently have better tolerances and are less prone to having metal particles being shaved off.
At that time, Tesla service has been very backed up here in Massachusetts so my appointment for the drive unit replacement was scheduled six weeks out. I put on another 4,000 miles during that wait time, with an increasingly louder drive unit, before it was finally replaced.
When Tesla replaces a drive unit, they replace both the drive unit and inverter as you can see from a copy of the parts list. The last letter in the drive unit part number (“M” in my case) seems to indicate the generation of the drive unit. The later the letter the better, with the “Q”s seeming to have the best longevity according to the forums.
I’m happy to say that I’ve logged 8,000 miles of happy and noise-free driving after my drive unit replacement. The replacement was done recently so my guess is that I have a newer unit, and thus hope this will be my only replacement.
Thankfully for all of us, Tesla has a first class warranty and level of service. While it goes without saying that inconveniences such as this may happen, rest assured that Tesla has you covered and will always strive to make things right.
Elon Musk
Tesla Semi’s official battery capacity leaked by California regulators
A California regulatory filing just confirmed the exact battery size inside each Tesla Semi variant.
A regulatory filing published by the California Air Resources Board in April 2026 has put official numbers on what Tesla Semi owners and fleet buyers have long wanted confirmed: the exact battery capacities of both the Long Range and Standard Range Semi truck variants. CARB is California’s independent air quality regulator, and it certifies zero-emission powertrains before they can be sold or operated in the state. When a manufacturer submits a vehicle for certification, the resulting executive order becomes a public document, making it one of the most reliable sources for confirmed production specs on any EV.
The document lists two certified powertrain configurations. The Long Range Semi carries a usable battery capacity of 822 kWh, while the Standard Range version comes in at 548 kWh. Both use lithium-ion NCMA chemistry and share the same peak and steady-state motor output ratings of 800 kW and 525 kW respectively. Cross-referencing Tesla’s published efficiency figure of approximately 1.7 kWh per mile under full load, the 822 kWh pack supports roughly 480 miles of real-world range, which aligns closely with Tesla’s advertised 500-mile figure for the Long Range trim. The 548 kWh Standard Range pack works out to approximately 320 miles, again consistent with Tesla’s stated 325-mile target.
Here is a direct comparison of the two versions based on the CARB filing and published specs:
| Tesla Semi Spec | Long Range | Standard Range |
| Battery Capacity | 822 kWh | 548 kWh |
| Battery Chemistry | NCMA Li-Ion | NCMA Li-Ion |
| Peak Motor Power | 800 kW | 525 kW |
| Estimated Range | ~500 miles | ~325 miles |
| Efficiency | ~1.7 kWh/mile | ~1.7 kWh/mile |
| Est. Price | ~$290,000 | ~$260,000 |
| GVW Rating | 82,000 lbs | 82,000 lbs |
The timing of this certification is not incidental. On April 29, 2026, Semi Programme Director Dan Priestley confirmed on X that high-volume production is now ramping at Tesla’s dedicated 1.7-million-square-foot facility in Sparks, Nevada. A key advantage of the Nevada location is vertical integration: the 4680 battery cells powering the Semi are manufactured in the same complex, eliminating the supply chain bottleneck that had delayed the program for years.
Tesla’s long-term goal is to reach a production capacity of 50,000 trucks annually at the Nevada factory, which would represent roughly 20 percent of the entire North American Class 8 market. With CARB certification now in hand and the production line running, the regulatory and manufacturing groundwork for that target is in place.
Tesla became the first company to pass the United States government’s new Advanced Driver Assistance Systems (ADAS) testing with the Model Y, completing each of the new tests with a passing performance.
In a landmark announcement on May 7, the National Highway Traffic Safety Administration (NHTSA) declared the 2026 Tesla Model Y the first vehicle to pass its newly ADAS benchmark under the New Car Assessment Program (NCAP).
Model Y vehicles manufactured on or after November 12, 2025, met rigorous pass/fail criteria for four newly added tests—pedestrian automatic emergency braking, lane keeping assistance, blind spot warning, and blind spot intervention—while also satisfying the program’s original four ADAS requirements: forward collision warning, crash imminent braking, dynamic brake support, and lane departure warning.
The NHTSA has just officially announced that the 2026 @Tesla Model Y is the first vehicle model to pass the agency’s new advanced driver assistance system tests.
2026 Tesla Model Y vehicles, manufactured on or after Nov. 12, 2025, successfully met the new criteria for four… pic.twitter.com/as8x1OsSL5
— Sawyer Merritt (@SawyerMerritt) May 7, 2026
NHTSA administration Jonathan Morrison hailed the achievement as a milestone:
“Today’s announcement marks a significant step forward in our efforts to provide consumers with the most comprehensive safety ratings ever. By successfully passing these new tests, the 2026 Tesla Model Y demonstrates the lifesaving potential of driver assistance technologies and sets a high bar for the industry. We hope to see many more manufacturers develop vehicles that can meet these requirements.”
The updates to NCAP, finalized in late 2024 and effective for 2026 models, reflect growing recognition that ADAS features are no longer optional luxuries but essential tools for preventing crashes.
Pedestrian automatic emergency braking, for instance, targets one of the fastest-rising causes of roadway fatalities, while blind spot intervention and lane keeping assistance address common sources of side-swipes and run-off-road incidents. By incorporating objective, performance-based evaluations rather than mere presence of the technology, NHTSA aims to give buyers clearer data on real-world effectiveness.
This milestone arrives at a pivotal moment when vehicle autonomy is transitioning from science fiction to everyday reality.
Tesla’s Full Self-Driving (FSD) software and the impending rollout of robotaxis underscore a broader industry shift toward higher levels of automation. Yet regulators and consumers remain cautious: safety data must keep pace with technological ambition.
The Model Y’s perfect score on these ADAS benchmarks validates that current driver-assist systems—when engineered rigorously—can dramatically reduce human error, which still accounts for the vast majority of crashes.
For Tesla, the result reinforces its long-standing claim of building the safest vehicles on the road. More importantly, it signals to the entire auto sector that meeting elevated federal standards is achievable and expected.
As autonomy edges closer to Level 3 and beyond, where drivers may disengage more fully, such independent verification becomes critical. It builds public trust, informs purchasing decisions, and accelerates the development of systems that could one day eliminate tens of thousands of annual traffic deaths.
In an era when software-defined vehicles promise transformative mobility, the 2026 Model Y’s NHTSA triumph is more than a manufacturer accolade—it is a regulatory green light that autonomy’s future must be built on proven, testable safety foundations. The bar has been raised. The industry, and the roads we share, will be safer for it.
Tesla is going to fix the nearly 219,000 vehicles that it recalled due to an issue with the rearview camera with a simple software update, giving owners no need to travel to a service center to resolve the problem.
Tesla is formally recalling 218,868 U.S. vehicles after regulators discovered a software glitch that can delay the rearview camera image by up to 11 seconds when drivers shift into reverse.
The affected models include certain 2024-2025 Model 3 and Model Y, as well as 2023-2025 Model S and Model X vehicles running software version 2026.8.6 and equipped with Hardware 3 computers. The National Highway Traffic Safety Administration (NHTSA) determined the lag violates Federal Motor Vehicle Safety Standard 111 on rear visibility and could increase crash risk.
Yet this is no ordinary recall. Owners do not need to schedule a service-center visit, hand over keys, or wait for parts.
Tesla fans call for recall terminology update, but the NHTSA isn’t convinced it’s needed
Tesla identified the issue on April 10, halted further deployment of the faulty firmware the same day, and began pushing a corrective over-the-air (OTA) software update on April 11.
By the time the NHTSA posted the recall notice on May 6, more than 99.92 percent of the affected fleet had already received the fix. Tesla reports no crashes, injuries, or fatalities linked to the glitch.
The episode underscores a deeper problem with regulatory language. For decades, “recall” meant hauling a vehicle to a dealership for hardware repairs or replacements. That definition no longer fits software-defined cars. When a fix arrives wirelessly in minutes — identical to an iPhone update — the term evokes unnecessary alarm and misleads the public about the actual risk and remedy.
Elon Musk has repeatedly called for exactly this change. After earlier NHTSA actions, he stated plainly: “The terminology is outdated & inaccurate. This is a tiny over-the-air software update.” On another occasion, he added that labeling OTA fixes as recalls is “anachronistic and just flat wrong.”
The terminology is outdated & inaccurate. This is a tiny over-the-air software update. To the best of our knowledge, there have been no injuries.
— Elon Musk (@elonmusk) September 22, 2022
Musk’s point is simple: regulators must evolve their vocabulary to match the technology. Traditional recalls involve physical intervention and downtime; OTA updates do not. Retaining the old label distorts consumer perception, inflates perceived defect rates, and slows the industry’s shift to faster, safer software iteration.
Tesla’s rapid, remote remedy demonstrates the safety advantage of over-the-air capability. Problems that once required weeks of dealer appointments are now resolved in hours, often before most owners notice. As more automakers adopt software-first designs, the entire regulatory framework needs to catch up.
Updating “recall” terminology would align language with reality, reduce public confusion, and recognize that modern vehicles are no longer static hardware — they are continuously improving computers on wheels.
For the 219,000 Tesla owners involved, the process is already complete. The camera works, the car is safe, and no one left their driveway. That is the new standard — and the vocabulary should reflect it.
Tesla Semi’s official battery capacity leaked by California regulators
Tesla crushes NHTSA’s brand-new ADAS safety tests – first vehicle to ever pass
