The quest to maximize electric vehicle efficiency — in driving and charging — and to lower the risk of fires has engineers at automakers and elsewhere looking at everything under the hood, including the coolant coursing through an EV’s tubular veins.

EV and internal combustion engine vehicle cooling systems share no mechanical parts, and they operate under different temperature
ranges. But there is one thing they have in common, said Tom Corrigan, director of EV technology at Prestone Products Corp. — ethylene glycol coolant.

That’s about to change.

The problem with ethylene glycol coolant in battery-electric and in hydrogen fuel cell vehicles is that when it contacts the metals, plastics
and other components in the system, it can, over time, become ionized. This means the coolant gains electrons, reducing the efficiency of BEVs and potentially causing major problems in fuel cell vehicles.

“Essentially, EVs are borrowing the internal combustion engine fluid,” Corrigan told Automotive News. “We are going to see a shift in that in the next one to two years.”

The primary driver for that shift, he said, is safety. It comes down to the electrical conductivity of the fluid — the way in which ICE coolants use corrosion inhibitors in their formulation.