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Do electric cars need oil?

The question can definitely be answered with yes. Although the requirements for lubricants will change in part, electric cars will continue to need oil. This applies, for example, to components such as transmissions, wheel bearings and air conditioning systems.

However, the classic engine oil used in combustion engines is no longer used in electric cars. Since the axles in electric cars are supplied with energy and driven by a battery, the moving parts that a combustion engine needs for propulsion, such as pistons and cylinders, are no longer needed. In the electric engine there are no friction partners that require lubrication.

Electric car at a charging station
Electric cars refuel at charging stations

Our lubricants for electric cars

ADDINOL EV FLUID ET

Application area:

Automatic transmissionsViscosity class:

SAE J 306

The most important lubrication points in electric cars

What are the lubrication points on electric cars?

In an electric car, there are still some components that require lubricants. These include:

  • Transmissions
  • Central locking and other sensor motors
  • Roller bearings in the electric engine
  • Air conditioning
  • Wheel bearing
  • ABS/ESP
Lubrication points from an electric car
Representation of the lubrication points in an electric car

In electric cars, the transmission works largely without gear shifting and is only single or two-stage. In the transmission of electric cars, very high speeds can occur at times, resulting in increased thermal and physical stress on the oil. The transmission oil for electric cars requires high heat resistance and robustness.

Lubricating greases are used in the electric engine, in auxiliary units and in the central locking system. They must withstand harsh conditions in the electric car and absorb high temperatures and rotational speeds in the roller bearing of the electric engine. At the same time the greases must be compatible with many materials such as copper, plastics and electronic components.

To keep the batteries in the electric car functional, a good cooling system is essential. Media such as air and water are hardly sufficient for cooling. For this reason, the first cooling liquids for electric cars are currently being developed, which are designed for the special construction of the battery cells.

Comparison of lubrication points in electric cars, hybrid cars and cars with combustion engines

In the following table we list important lubricants for cars and briefly summarise whether the lubricant is still needed and if so, with any special features. The types electric engine, hybrid engine and combustion engine are compared.

Lubricant Combustion engine Hybrid engine Electric engine
Engine oil Is needed Is required, depending on the construction multi-grade oil or 4-stroke oil is required Not required
Transmission oil Is needed Is needed Is needed, with new requirements
Greases Is needed Is needed Is needed, with new requirements
Hydraulic oil Is needed Is needed Is needed
Functional fluids such as coolant, brake fluid etc. Is needed Is needed Is needed, to an increased extent

How does oil for electric cars differ from oil for cars with combustion engines?

The different construction of electric cars compared to cars with combustion engines inevitably results in different requirements on the lubricants. Therefore, special lubricants for electric cars have to be developed.

Lubricants for electric cars must have the following properties:

  • Dielectric properties for lubricants in direct contact with electrical components to prevent short circuits and sparks
  • Compatibility with various materials such as copper (high electrical conductivity) and polymeric cable sheathing
  • Cooling properties due to good heat dissipation of the electrical energy
  • Wear, oxidation and corrosion protection for the entire system
  • Strict water separation to prevent electrical flashovers between live components

There are currently no general approvals and specifications for lubricants in electric cars. The different construction methods of electric vehicles make standardisation even more difficult. Therefore, the current lubricants for electric cars are individually adapted to specific applications.

Copper sulphide test with ADDINOL ETF technology
With the wrong oil copper sulphide is formed on copper elements (left), a right additive prevents this (right test with ADDINOL ETF technology)

Research contract for lubricant manufacturers

As a lubricant manufacturer, ADDINOL is rising to the new challenges of e-mobility and developing solutions. This addresses the increased demand for electric cars. Electric cars are already a common sight on our roads, and the number of new registrations is set to rise further in the coming years. Buying an electric car is becoming increasingly attractive. Both the network of charging stations and battery capacity are being expanded. Electric cars are now also suitable for long-distance travel thanks to their increased range and short charging times.

Lubricant manufacturers will also contribute to this development. Efficient and individually formulated lubricants can improve the performance of electric cars by optimising power transmission, resisting heat and cooling key components. The first products of ADDINOL for electric mobiles are already in planning.

Contact

Mayka Nehrkorn

Mayka Nehrkorn

Product Manager Automotives