Do Electric Vehicles Need Lubricants? A Guide to EV Cooling and Drivetrain Fluids

What Disappears in a BEV

A battery-electric vehicle eliminates an entire category of maintenance that defined internal combustion ownership:

• Engine oil and oil filters — there is no internal combustion engine to lubricate.
• Spark plugs and ignition components — no combustion means nothing to ignite.
• Exhaust system fluids and catalytic converters — no combustion byproducts to treat.
• Multi-speed transmission fluid changes — most BEVs use a single-speed reduction gear rather than a multi-speed automatic transmission, which is mechanically simpler and typically services less often.

According to Fortune Business Insights (July 2026), electric vehicles require significantly fewer routine fluid changes than combustion vehicles specifically because they lack engines, multi-speed transmissions and exhaust systems. That's real, and it's also the source of a common misconception: fewer fluid touchpoints gets rounded up, in a lot of marketing and casual conversation, to no fluids at all.

That's the gap this guide is addressing.

What Still Needs Lubrication

What remains in a BEV is smaller in scope, but not optional.

Electric motor bearings. The rotor spins on bearings, and those bearings need lubrication like any other rolling-element bearing. Most electric motors use grease-lubricated bearings rather than oil-bath systems, and bearing wear is not a minor detail — according to Machinery Lubrication, bearing-related issues account for 50 to 65 percent of electric motor failures industry-wide, which makes bearing lubrication one of the more consequential, if unglamorous, maintenance items on an EV.

The reduction gear. Almost all current BEVs use a single-speed reduction gear, sometimes paired with a differential, instead of a multi-speed transmission. That gearset still has meshing gears and bearings that need a lubricating film — either a dedicated gear oil or an ATF-type fluid, depending on the manufacturer's design. It's serviced less often than a traditional transmission, but it isn't maintenance-free.

A trend toward lower viscosity. Because parasitic drag on the motor directly costs range, EV-specific gear oils and greases are trending toward lower viscosities than their combustion-vehicle equivalents — a shift discussed in peer-reviewed lubricant engineering literature covering EV and hybrid driveline requirements in Lubricants (MDPI, 2021).

Lower viscosity improves efficiency, but it also reduces the oil film's margin for error, which is one reason EV-specific formulations exist rather than reusing conventional automotive gear oil. The same literature also discusses the changing performance requirements for EV-specific greases as electric drivetrains place lubrication close to motors, bearings and electrical components.

Cooling Requirements

Thermal management is arguably where an EV's fluid needs grow rather than shrink.

A typical EV runs two to three separate cooling loops: a lower-temperature loop dedicated to the battery pack, a higher-temperature loop for the drive unit, motor and power electronics, and — in most vehicles — a cabin air-conditioning refrigerant loop, all coordinated by the vehicle's thermal management system, according to IDTechEx's EV thermal management research (December 2024).

For the battery specifically, liquid cooling through cold plates or coolant channels has become the dominant approach in modern production EVs. Water-glycol remains an important coolant type in these indirect battery thermal-management systems, as discussed in IDTechEx's analysis of EV cooling systems.

A more advanced approach, immersion cooling, submerges battery cells directly in a dielectric fluid rather than routing coolant through external plates. IDTechEx's research on direct dielectric and immersion cooling notes that the fluid comes directly into contact with the cells and must provide the electrical and thermal characteristics required by the system. Flame-retardant dielectric fluids can also help limit thermal-runaway propagation.

This is still an emerging technique rather than the mainstream default, but battery safety requirements are becoming more demanding. China's GB 38031-2025 Electric Vehicles Traction Battery Safety Requirements introduce updated requirements covering areas including thermal propagation, bottom impact and safety testing following fast-charging cycles.

Either approach — plate cooling or immersion — depends on a fluid engineered for heat transfer first. That's a different design brief than a traditional lubricant.

Electrical Compatibility

This is the requirement with no real equivalent in a combustion vehicle.

Traditional lubricants are formulated to reduce friction and manage heat; electrical properties were never part of the specification, because engine oil never touches a live electrical circuit. That assumption breaks down in an EV. Fluids inside an e-axle or motor housing can sit in close proximity to copper windings, and in some architectures, in direct contact with electrically active components.

Two properties matter as a result:

• Controlled electrical conductivity. According to Mordor Intelligence's transmission fluid market analysis, electrified drivetrains require fluids formulated to manage electrical conductivity and reduce risks such as arcing — a requirement that is far less significant in a conventional gearbox.
• Copper compatibility. The same Mordor Intelligence analysis notes that EV-specific e-fluids must resist copper corrosion in motor windings while also helping remove heat from high-speed electric-drive components. The exact electrical and material-compatibility requirements depend on the motor architecture and should be confirmed against the OEM specification.

These electrical requirements are also reflected in research on the electrical properties of electric-vehicle gear oils, which examines conductivity and insulation performance in EV lubricant applications.

That's the practical reason conventional fluid selection cannot simply be carried over into every EV application — not marketing language, but a genuinely different design requirement.

Distributor Opportunity

For distributors, the shift toward EVs is not simply a threat to lubricant volume — it's a category shift, not a category loss.

According to Arizton's U.S. Electric Vehicle Fluids Market report, the market was valued at about $459 million in 2021 and is projected to reach approximately $1.72 billion by 2027, representing a CAGR of 24.58 percent over the forecast period.

Fewer litres per vehicle does not necessarily mean a smaller commercial opportunity, particularly as EV-specific fluids — engineered for dielectric properties and thermal performance rather than viscosity alone — typically carry a different specification profile than a conventional gear oil or ATF.

What this means practically for a distributor:

• The product line looks different. EV coolant, electric motor fluid and EV transmission fluid are a separate catalogue from conventional engine and gear oils, not a variant of them.
• Technical documentation matters more, not less. Electrical properties, thermal performance and copper compatibility become part of what a buyer may need to evaluate before ordering — generic viscosity-grade information isn't enough on its own.
• Early positioning has value. As the vehicle parc shifts, distributors already carrying a credible EV fluid line have a head start with workshops and fleets that are servicing their first EVs.

TERZO's Electric Vehicle Fluid Oil range, including the TERZO Trans EV Fixed Gear Ratio Oil, is built around this shift.

For a closer look at the EV fluids market itself, see TERZO's related market analysis.

Download the EV Fluid Catalogue