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.
RELATED:
StoreDot closes in on U.S. market entry with launch of R&D campus in California
What are your thoughts? Let me know at zach@teslarati.com, find me on X at @zacharyvisconti, or send us tips at tips@teslarati.com.
News
Tesla Cybercab tests are going on overdrive with production-ready units
Tesla is ramping its real-world tests of the Cybercab, with multiple sightings of the vehicle being reported across social media this week.
Tesla is ramping its real-world tests of the Cybercab, with multiple sightings of the autonomous two-seater being reported across social media this week. Based on videos of the vehicle that have been shared online, it appears that Cybercab tests are underway across multiple states.
Recent Cybercab sightings
Reports of Cybercab tests have ramped this week, with a vehicle that looked like a production-ready prototype being spotted at Apple’s Visitor Center in California. The vehicle in this sighting was interesting as it was equipped with a steering wheel. The vehicle also featured some changes to the design of its brake lights.
The Cybercab was also filmed testing at the Fremont factory’s test track, which also seemed to involve a vehicle that looked production-ready. This also seemed to be the case for a Cybercab that was spotted in Austin, Texas, which happened to be undergoing real-world tests. Overall, these sightings suggest that Cybercab testing is fully underway, and the vehicle is really moving towards production.
Production design all but finalized?
Recently, a near-production-ready Cybercab was showcased at Tesla’s Santana Row showroom in San Jose. The vehicle was equipped with frameless windows, dual windshield wipers, powered butterfly door struts, an extended front splitter, an updated lightbar, new wheel covers, and a license plate bracket. Interior updates include redesigned dash/door panels, refined seats with center cupholders, updated carpet, and what appeared to be improved legroom.
There seems to be a pretty good chance that the Cybercab’s design has been all but finalized, at least considering Elon Musk’s comments at the 2025 Annual Shareholder Meeting. During the event, Musk confirmed that the vehicle will enter production around April 2026, and its production targets will be quite ambitious.
News
Tesla gets a win in Sweden as union withdraws potentially “illegal” blockade
As per recent reports, the Vision union’s planned anti-Tesla action might have been illegal.
Swedish union Vision has withdrawn its sympathy blockade against Tesla’s planned service center and showroom in Kalmar. As per recent reports, the Vision union’s planned anti-Tesla action might have been illegal.
Vision’s decision to pull the blockade
Vision announced the blockade in early December, stating that it was targeting the administrative handling of Tesla’s facility permits in Kalmar municipality. The sympathy measure was expected to start Monday, but was formally withdrawn via documents sent to the Mediation Institute and Kalmar Municipality last week.
As noted in a Daggers Arbete report, plans for the strike were ultimately pulled after employer group SKR highlighted potential illegality under the Public Employment Act. Vision stressed its continued backing for the Swedish labor model, though Deputy negotiation manager Oskar Pettersson explained that the Vision union and IF Metall made the decision to cancel the planned strike together.
“We will not continue to challenge the regulations,” Petterson said. “The objection was of a technical nature. We made the assessment together with IF Metall that we were not in a position to challenge the legal assessment of whether we could take this particular action against Tesla. Therefore, we chose to revoke the notice itself.”
The SKR’s warning
Petterson also stated that SKR’s technical objection to the Vision union’s planned anti-Tesla strike framed the protest as an unauthorized act. “It was a legal assessment of the situation. Both for us and for IF Metall, it is important to be clear that we stand for the Swedish model. But we should not continue to challenge the regulations and risk getting judgments that lead nowhere in the application of the regulations,” he said.
Vision ultimately canceled its planned blockade against Tesla on December 9. With Vision’s withdrawal, few obstacles remain for Tesla’s long-planned Kalmar site. A foreign electrical firm completed work this fall, and Tesla’s Careers page currently lists a full-time service manager position based there, signaling an imminent opening.
Tesla Semi Program Director Dan Priestly teased the major improvements to the all-electric Class 8 truck on Thursday night, following the company’s decision to overhaul the design earlier this year.
Priestley said he drove the Semi on Thursday, and the improvements appear to be welcomed by one of the minds behind the project. “Our customers are going to love it,” he concluded.
Just drove the redesigned Semi. Our customers are going to love it. https://t.co/KZ88sf1CDL
— Dan Priestley (@danWpriestley) December 19, 2025
The small detail does not seem like much, but it is coming from someone who has been involved in the development of the truck from A to Z. Priestley has been involved in the Semi program since November 2015 and has slowly worked his way through the ranks, and currently stands as the Director of the program.
Tesla Semi undergoes major redesign as dedicated factory preps for deliveries
Tesla made some major changes to the Semi design as it announced at the 2025 Annual Shareholder Meeting that it changed the look and design to welcome improvements in efficiency.
Initially, Tesla adopted the blade-like light bar for the Semi, similar to the one that is present on the Model Y Premium and the Cybertruck.
Additionally, there are some slight aesthetic changes to help with efficiency, including a redesigned bumper with improved aero channels, a smaller wraparound windshield, and a smoother roofline for better aero performance.
All of these changes came as the company’s Semi Factory, which is located on Gigafactory Nevada’s property, was finishing up construction in preparation for initial production phases, as Tesla is planning to ramp up manufacturing next year. CEO Elon Musk has said the Semi has attracted “ridiculous demand.”
The Semi has already gathered many large companies that have signed up to buy units, including Frito-Lay and PepsiCo., which have been helping Tesla test the vehicle in a pilot program to test range, efficiency, and other important metrics that will be a major selling point.
Tesla will be the Semi’s first user, though, and the truck will help solve some of the company’s logistics needs in the coming years.
Tesla Cybercab tests are going on overdrive with production-ready units
Tesla gets a win in Sweden as union withdraws potentially “illegal” blockade
