Electric vehicles require specialized lubricants to ensure safe, efficient and low maintenance performance of their drivetrain, battery pack and mechanical components. In this article we explain the major lubrication requirements of EV.
As we are progressing towards a society where technology should be eco-friendly and sustainable, electric vehicles (EV) are here to stay. The lubrication challenges of EV differ from those of internal combustion engines (ICE). It calls for a new range of lubricants and fluids, specifically tailored to the performance requirements of the electrical and gear components in electric vehicles.
Why electric vehicles need specific lubricants?
Many people think that, given the simplicity of an electric vehicle, the need for tribologists would decrease. It seems logic without moving parts in the battery and only a few bearings for the engine and transmission line. However, using existing ICE-lubricants to lubricate electric vehicles is a bad idea.
Here’s why:
- The load and relative motion of the mechanical components in an EV differs from those in ICE. In many cases, the E-Motor lubricant also lubricates the (integrated) transmissions. Stresses on the bearings and gear components of EVs are significantly higher due to the high instantaneous torque of the E-Motor.
- In an EV, the lubricant in contact with a variety of materials such as metals like steel, aluminium and copper but also with elastomers, plastics and insulators.
- EV lubricants also needs to have enhanced electrical properties to ensure optimal safety in combination with electrical components and specific thermal conductivity properties for precise thermal management of the powertrain ensuring highest efficiency under all driving and climate conditions.
To guarantee a safe and efficient operation of an electric vehicle, you need specifically developed lubricants.
Looking for the best lubricant for your electric vehicle?
Lubrication requirements of electric vehicles
When designing or selecting a lubricant for electric vehicles, you should take into account the following E-Motor characteristics:
- High stresses on mechanical components due to the high E-Motor torque.
- High speed bearings: The bearings in EV rotate at higher speeds compared to ICE.
- New heat sources: Cooling is an important task of the lubricant. Due to the higher rotation speeds of the bearings, they dissipate more heat. And there is yet another extra heat source to take into account: the Joule losses in the motor coils.
- Optimized thermal management properties of the EV-lubricant are crucial too. Heat capacity and thermal conductivity defines the thermal management properties of the EV-lubricant. Optimizing these enable highest efficiency and range the electric vehicle.
- Material challenges: The lubricant flows on components in different materials, such as aluminium, steel, copper and polymers. Material deterioration such as copper corrosion and plastic degradation is a serious issue to consider.
- Low maintenance: Electric vehicles are considered to require very little maintenance. Needless to say, EV owners expect the same long-lasting capabilities of the lubricants used in their vehicles.
- Electric conductivity: Since the lubricants in electric vehicles are in close contact with electric components, the lubricant conductivity should be meticulously designed. High conductivity can lead to current leakage in the motor casing, while low conductivity can result in charge accumulation.. When the electric potential difference is too high, an electric discharge may occur, possibly leading to component damage and lubricant deterioration.
EV lubricants development: work for experts
Developing lubricants for electric vehicles is a big challenge. Car manufacturers have their own unique electric motor design, requiring a specific lubricant for the best performance of their electric motors.
The technical requirements of EV lubricants are much more extensive to that of ICEs. They must not only focus on anti-wear performance, friction reduction and efficiency, but also on lubrication of heavily loaded transmission and differentials, electrical compatibility, material compatibility with a variety of materials and elaborated thermal management properties for highest efficiency.
In our specialised Research & Development Centres we develop and continuously improve specialized high-performance lubricants for EV (and also for ICE and hybrid vehicles).
Q8Oils have developed a new range of transmission fluids and coolants for e-vehicles.
| Product | Specification |
|---|---|
| Q8 Auto H-EV DCT | Q8 Auto H-EV DCT is a synthetic Dual Clutch Transmission fluid for Hybrid vehicles. This product offers outstanding frictional performance and provides immediate lubrication after cold start which results in high resistance against wear. Due to the excellent oxidation, shear and thermal stability Q8 Auto H-EV DCT extends transmission life and extended Oil Drain Intervals. Further more Q8 Auto H-EV DCT has outstanding elastomer compatibility. |
| Q8 Auto H-EV CVT | Q8 Auto H-EV CVT is a universal synthetic Hybrid-EV CVT Fluid. Q8 Auto H-EV CVT limits transmission wear and extends transmission life, giving excellent metal-metal friction protection and torque transfer. Due to synthetic technology Q8 Auto H-EV CVT offers excellent oxidation stability, withstands high temperatures and good elastomer compatibility and immediate lubrication after cold starting. |
| Q8 Auto H-EV ATF | Q8 Auto H-EV ATF is a synthetic Hybrid-EV Automatic Transmission Fluid for E-Automatic Transmissions with
extended drain intervals. Q8 Auto H-EV ATF delivers Outstanding resistance against wear and extends transmission life and excellent oxidation and thermal stability as well as improved frictional performance and shear stability. Q8 Auto H-EV ATF offers improved fuel economy, and provides immediate lubrication after cold start and protects with outstanding elastomer compatibility |
| Q8 Auto ETF | Q8 Auto ETF is a superior synthetic ETF fluid for power electronics. Q8 Auto ETF offer highest wear protection for both gears and bearings. This high level of performance enables protection of the mechanical part whilst operating at low and high speed. Q8 Auto ETF offers highest level of thermal management properties enabling optimized efficiency and range. |
| Q8 TMF-EV | Q8 TMF EV is a superior premixed OAT based Thermal Management Fluid that protects against freezing, boiling and corrosion of the cooling system. The thermal management fluid transfers the heat of the battery further contributing to optimized efficiency and range. The long life properties of the Q8 TMF-EV is obtained by non-depleting corrosion inhibitors. |
| Q8 Brake Fluid DOT 5.1 | Q8 Brake FLuid DOT 5.1 is a high performance Long Life Fully Synthetic Brake Fluid recommended for all types of hydraulic actuated brake & clutch systems, especially designed for anti-locking braking systems (ABS) and Electronic Stability Program (ESP) systems. This non-silicone base
fluid is designed in accordance with DOT 5.1, and fulfils also DOT 4 and DOT 2 manufacturers’ recommendations. Formulated for best results in safe braking at most severe conditions |
