By Rick Cotta

January 30, 2022

Most EVs have a transmission of sorts (nearly all having just one speed) containing a lubricant that may need to be checked and perhaps even replaced — though replacement, if needed, isn’t typically done very often. Whether and when one needs to either check the transmission lubricant or replace it can be determined by consulting the maintenance section of the vehicle’s owner’s manual.

Three of the most popular EVs are the Chevrolet Bolt EV, Nissan Leaf and Tesla Model 3. Of those, only the Leaf’s maintenance schedule even mentions checking the transmission lubricant level (called “Reduction gear oil”), and while that’s supposed to be done yearly, it may be only a visual check for leakage. Other manufacturers, meanwhile, may include that as part of a dealer checkup even if it’s not specifically mentioned in the maintenance schedule. Through eight years or 120,000 miles — as far as the maintenance schedule goes — there are no recommended Reduction gear oil changes for the current-generation Leaf.

There are other fluids besides oil, however, that may need to be changed. One is brake fluid, which Nissan recommends changing on the Leaf every one or two years (depending on the model year); Tesla recommends checking and to “replace if necessary” (how that’s determined is unclear) every two years; and Chevrolet recommends replacing every five years.

Chevy also recommends you “drain and fill vehicle coolant circuits” — which provide climate control for the cabin and what’s called thermal management for the battery and charger — every five years. This coolant is often similar to regular engine coolant. Not all EVs cite this interval: The Tesla’s Model 3 manual states, “Your battery coolant does not need to be replaced for the life of your vehicle under most circumstances.”

While electric vehicles generally need far less maintenance than gas ones, they certainly aren’t “maintenance-free” — even though traditional oil changes aren’t among the requirements.