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Effects of Winter on Tesla Battery Range and Regen
Winter conditions has begun to set in here in New England with temperatures not exceeding the 20’s. Thankfully I’ve already prepared my winter wheels and tires in advance so I’m not overly worried about the potential for snow, however I’m quickly learning the effects of winter on the battery and overall energy efficiency.
Cabin Temperature
Preheating the cabin temperature through the mobile Tesla Motors app.
The first order of business is making sure I’m comfortable when I get into the car each day. This means preheating the Model S cabin temperature through the Tesla App (if I happen to remember to) or, better yet, have it scheduled to automatically preheat via the VisibleTesla app.
My daily schedule looks something like this: VisibleTesla preheats the car 30 minutes before I enter and while it’s still plugged in from my overnight charge. This ensures I enter a warm car every morning with no affect on my range – the best of both worlds!
Leaving for work at the end of the day, however, is a bit more erratic so I usually use the Tesla App to preheat on an ad-hoc basis. I realize that this preheating will eat into my overall battery range, but I’m not overly concerned because I have plenty of range to spare even with a 100 mile commute each day. It’s well worth it for a little more comfort.
I enjoy turning on the air conditioner during the summer months but getting into a warm car in the dead of winter is even better!
Limited Regenerative Braking
Prior to the winter, the only times I have experienced limited regenerative braking (regen) was directly after performing range charges in anticipations of my Tesla road trip adventures. The Tesla battery does not have the capacity to receive additional energy (when at a 100% state of charge) thus it disables regenerative braking all together.
Winter months, however, bring a completely different experience with regen. When the Model S is cold it limits the ability to regen since the batteries need to be at an optimal temperature before it receives any additional charge.
A dashed yellow line appears on the center display indicating that regenerative braking is limited. If you’ve been accustomed to driving with regen on, this new behaviour (with regen disabled) will feel and drive very differently.
I found myself quickly rolling towards the cars in front of me as I instinctively ignored the brakes and assumed that the car would just come to a gradual stop by letting go of the accelerator pedal. That obviously didn’t happen with regen limited. You’ll need to use your brakes so be careful not to “over press” it as you quickly adjust to driving with brakes again.
This winter-induced form of limited regeneration lasts for a very long. I wasn’t sure if the lack of regen was isolated to the weather conditions for that particular day so I decided to log my results over a larger sample of several days.
Here’s what I noticed about the effects of winter on Tesla’s regenerative braking:
- There appears to be a linear easing off of the “regen cap” through the first 30 minutes. At 0 miles, when the car is just started, the amount of regen is capped at 20 kW.
- 25 minutes into my drive, the regen cap is loosened to 40 kW.
Graph depicting the amount of energy that can be regained through regen over time.
As you can see from some of my data points, it took me over 45 minutes of driving (30 miles covered) before the regenerative braking behavior was back to normal — that’s almost my entire drive home!
I’ve been experimenting with various approaches to avoid the regen capping. One of which is timing my overnight charge so that it completes right at the time I’m about to leave for work. This ensures that the batteries are at a good temperature, by the time I begin driving, and with no regen cap in place. Timing it perfectly can be tricky.There’s been a few occasions where my charge completed earlier than expected and as a result the batteries cooled off before I got to drive.Here again VisibleTesla can help, but it’s an area that I wish Tesla would address directly —
add a feature to allow users to specify the END time for a charge as opposed to the start time. The Model S should calculate when charging begins based on the set end time.
I’ve been experimenting with ways to reduce the after-work limited regenerative braking occurrences but since there’s no charging infrastructure at my work, I can’t pre-warm the batteries. I’ve even tried warming up the cabin temperature in advance to see if this would have an impact on regenerative braking but unfortunately it doesn’t.
Higher Energy Use
Cold weather definitely affects energy use on the Model S. My tires, while great for winter, are less efficient — they’re not the low rolling resistance tires that came with the Model S. I’m also using extra energy for warming the cabin (despite my chilly 66 F year-round cabin temperature setting). The Model S is also using extra power when managing the battery temperature.
Prior to winter my average energy consumption was around 300-315 kWh/mi but now I’m averaging 350-365 kWh/mi or approximately 16% more energy used than summer months. I’m also using my brakes more during the winter, as a result of the limited regenerative braking, so that will also introduce more wear and tear.
One piece of advice from Tesla is to use seat heaters to warm yourself up over cabin heat. The seat heaters apply heat directly to your body and thus a more efficient use of energy. If you have your cabin temperature set at 72 F , try reducing it to 68 F and use your seat heaters to warm yourself up.
I’m sure I’ll be uncovering a lot more tips and interesting findings over the next few months especially as the snow storms start blowing in and temperatures dip into single digits! Stay tuned!
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
