Automotive chemical manufacturer Prestone is currently developing a low-conductivity electric vehicle (EV) coolant that scientists hope can increase EV efficiency.
While ethylene glycol is used in both gas vehicles and EVs, including Teslas, Prestone has increased its research and development budget for learning about less conductive cooling fluids over the past year, as detailed in a report from Automotive News on Friday. Prestone EV Director Tom Corrigan says that that won’t be the case in the future, as the company seeks to develop its own.
“Essentially, EVs are borrowing the internal combustion engine fluid,” Corrigan said. “We are going to see a shift in that in the next one to two years.”
The company has been testing its low-conductivity EV coolants in Ford Mustang Mach-E vehicles at its tech center in Danbury, Connecticut, in recent months. While initial offerings are roughly two years away and will still include ethylene glycol bases, Corrigan also says that petroleum-based dielectric coolants could replace the chemistry in future years.
Coolant types may also be dependent on battery chemistries, with lithium-iron phosphate (LFP), solid-state, and nickel manganese cobalt batteries likely all requiring different coolant makeups. Tesla writes on its website that its cooling systems currently use a phosphate and nitrate-free ethylene glycol-based coolant.
Ethylene glycol can ionize over time when it interacts with metals, plastics, and other necessary engine materials. As the coolant gains electrons, the overall efficiency of a battery-electric vehicle (BEV) is decreased. In addition, the coolant chemistry is expected to shift because of safety, as a BEV-friendly replacement for the corrosion inhibitors used in ICE coolants.
“Those ionize in the fluid and carry an electrical charge. If you have an issue where high-conductivity coolant contacts high-voltage electronics or the battery, it can lead to fire,” Corrigan explains. “So what we are working on is low-conductivity coolant.”
Scientists evaluate the electrical conductivity of coolants using a unit called microsiemens, which measures the conductivity per centimeter. In gas cars, experts expect to see between 3,000 and 5,000 microsiemens per centimeter, considered highly conductive, though it doesn’t negatively interact with gas vehicles in the same way it does for BEVs.
Instead, BEV makers are asking Prestone to develop a coolant with just 100 microsiemens per centimeter, while other fuel cell vehicles may require coolant conductivity levels of just 0.5 to 1.5 microsiemens, according to Corrigan.
“Every bit of increased conductivity is a loss of efficiency in the fuel cell. You’ve got to make the fluid very pure,” he notes.
Along with adding to the company’s R&D budget, Prestone added an additional five scientists and engineers in the department developing coolants for BEVs and fuel cells.
“We see where the future is going with EV coolants, and we want to be ready when the manufacturers are ready,” Corrigan says.
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News
Tesla begins Holiday Update rollout with some surprise features
On Monday, just a few days after Tesla first announced the Holiday Update, people started reporting that it was being deployed to owners.
Tesla has started the rollout of the 2025 Holiday Update, as several owners reported it had arrived in their cars via a software update.
Tesla’s Holiday Update is rolling out as Software Version 2025.44.25.1, and includes several new features. We did an extensive breakdown of what was included in another article, but we’ll list the new additions below:
- Grok with Navigation Commands (Beta) – Grok will now add and edit destinations.
- Tesla Photobooth – Take pictures inside your car using the cabin-facing camera
- Dog Mode Live Activity – Check on your four-legged friend on your phone through periodic snapshots taken of the cabin
- Dashcam Viewer Update – Includes new metrics, like steering wheel angle, speed, and more
- Santa Mode – New graphics, trees, and a lock chime
- Light Show Update – Addition of Jingle Rush light show
- Custom Wraps and License Plates – Colorizer now allows you to customize your vehicle even further, with custom patterns, license plates, and tint
- Navigation Improvements – Easier layout and setup
- Supercharger Site Map – Starting at 18 pilot locations, a 3D view of the Supercharger you’re visiting will be available
- Automatic Carpool Lane Routing – Navigation will utilize carpool lanes if enabled
- Phone Left Behind Chime – Your car will now tell you if you left a phone inside
- Charge Limit Per Location – Set a charge limit for each location
- ISS Docking Simulator – New game
- Additional Improvements – Turn off wireless charging pad, Spotify improvements, Rainbow Rave Cave, Lock Sound TRON addition
On Monday, just a few days after Tesla first announced the Holiday Update, people started reporting that it was being deployed to owners.
We noticed a new Tesla software update 2025.44.25.1 on a Model Y AWD LR (2022) in Florida, United States. View the rollout of this update here: https://t.co/rPqISQaNkM
— Teslascope (@teslascope) December 8, 2025
It seems the release is a bit of an apology to a particular group, as it has only made its way to Hardware 3 vehicles, particularly the ones using the AMD Ryzen chip.
Tesla has excluded FSD-purchased and subscribed vehicles that are utilizing Hardware 3, so it seems there is a strategy to this limited rollout.
Two Surprise Additions
Tesla has added two additional features with the Holiday Update, which include a new Storage Space for Dashcam feature that shows how much space you have used and remaining on your USB drive.
Additionally, Tesla gamified Supercharging with a new “Charging Passport” feature, which we reported on earlier today.
News
Tesla announces major milestone at Gigafactory Shanghai
First deliveries started in December 2019, with the first units being given to employees. By the end of 2020, the plant was building cars at a run rate of around 150,000 vehicles annually.
Tesla has announced a major milestone at its Chinese manufacturing facility, Gigafactory Shanghai, confirming on Monday that it had built its four millionth vehicle.
Tesla Gigafactory Shanghai first started building cars back in October 2019 with Model 3 assembly, just ten months after the company broke ground on the plant’s 86-hectare piece of land.
First deliveries started in December 2019, with the first units being given to employees. By the end of 2020, the plant was building cars at a run rate of around 150,000 vehicles annually. Production continued to ramp up, and by September 2023, less than three years after it started building Tesla’s EVs, it had built its two millionth vehicle.
Fast forward to December 2025, and Tesla has confirmed that four million cars have rolled off of production lines at the plant, a major milestone in the six short years it has been active:
Produced our 4 millionth vehicle at Gigafactory Shanghai🎉
Thanks to all our owners and supporters❤️ pic.twitter.com/DayVXUr220— Tesla Asia (@Tesla_Asia) December 8, 2025
The capacity at Giga Shanghai is exceeding 950,000 vehicles per year, and this year, the company has delivered 675,000 cars through the first three quarters. It is also the only plant to manufacture the Model Y L, a longer wheel-based configuration of the all-electric crossover that is exclusive to the Chinese market.
Gigafactory Shanghai’s four million cars have not all stayed within the domestic market, either. For a considerable period, the factory was exporting a significant portion of its monthly production to Europe, helping Gigafactory Berlin supplement some Model Y volume and all of its Model 3 deliveries. This is due to the Berlin plant’s exclusive production plans for the Model 3.
The site is one of the most crucial in the company’s global plans, and Gigafactory Shanghai’s incredible pace, which has led to four million production units in just about six years. It’s fair to say that it won’t be long until we’re seeing Tesla celebrate the plant’s five millionth vehicle produced, which should happen sometime late next year or in early 2027, based on its current manufacturing pace.
The company also builds the Megapack on the property in an adjacent Megafactory.
News
Tesla gamifies Supercharging with new ‘Charging Passport’
It will also include things like badges for special charging spots, among other metrics that will show all of the different places people have traveled to plug in for range.
Tesla is gamifying its Supercharging experience by offering a new “Charging Passport,” hoping to add a new layer to the ownership experience.
While it is not part of the Holiday Update, it is rolling out around the same time and offers a handful of cool new features.
Tesla’s Charging Passport will be available within the smartphone app and will give a yearly summary of your charging experience, helping encapsulate your travel for that year.
It will also include things like badges for special charging spots, among other metrics that will show all of the different places people have traveled to plug in for range.
Tesla has just introduced “Charging Passport,” a new yearly summary of your charging.
• Charging badges: Iconic Charging badge (for visiting places like the Tesla Diner, Oasis Supercharger, etc), Explorer badge, green saver badge, etc.
• Total unique Superchargers visited
•… pic.twitter.com/c1DHTWXpj7— Sawyer Merritt (@SawyerMerritt) December 8, 2025
Tesla will include the following metrics within the new Charging Passport option within the Tesla app:
- Charging badges: Iconic charging badges for visiting places like the Tesla Diner, Oasis Supercharger, etc., Explorer Badge, and more
- Total Unique Superchargers Visited
- Total Charging Sessions
- Total Miles Added during Charging Sessions
- Top Charging Day
- Longest Trip
- Favorite Charging Locations
This will give people a unique way to see their travels throughout the year, and although it is not necessarily something that is needed or adds any genuine value, it is something that many owners will like to look back on. After all, things like Spotify Wrapped and Apple Music Replay have been a great way for people to see what music they listened to throughout the year.
This is essentially Tesla’s version of that.
With a handful of unique Superchargers already active, Tesla is also building some new ones, like a UFO-inspired location in New Mexico, near Roswell.
Tesla is building a new UFO-inspired Supercharger in the heart of Alien country
Tesla begins Holiday Update rollout with some surprise features
Tesla announces major milestone at Gigafactory Shanghai
