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Polyglycol base oils for EV fluids

Are you a gear oil formulator, looking for base oils to help meet new e-fluid needs? Our synthetic polyglycol base oils are ideally suited for use in EV fluids.

The key benefits of our electric vehicle lubricants are clear

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  • Outstanding thermal properties (heat capacity and thermal conductivity)
  • Outstanding low friction coefficient
  • Hazard label free, readily biodegradable
  • Good viscosity-temperature behaviour

Shifting e-fluid efficiency into a higher gear

With the global electric vehicle (EV) market predicted to continue growing strongly in the coming years, demand for high-quality e-drive lubricants is likely to soar. As electric motors and associated reduction gears become increasingly compact, with changing requirements in terms of energy efficiency and heat removal, OEMs, gear oil formulators and researchers are on the lookout for base oils to help meet these new e-fluid needs. The properties of Clariant’s synthetic polyglycol base oils make them ideally suited for use in EV fluids.

Covering a range of needs with a range of proven properties

Today’s EV fluids (for lubrication and cooling of the latest electric motors and transmissions) have to meet a range of requirements encompassing traditional lubrication capabilities such as reduced friction and energy efficiency in addition to heat transfer, oxidation stability, temperature resistance, conductivity and durability.

Effective cooling is particularly important in today’s EVs, as electric motor drives (e-drives) generate significant heat, which must be conveyed away from the drive unit.

Clariant has carried out comprehensive testing of four synthetic polyglycol base oils encompassing a range of properties to demonstrate their suitability for EV fluid applications


E01 P


E02 A


E03 A


E04 E

PAO 3.6

Viscosity index


Viscosity at 40 °C (mm2 s-1)

 13  12  13  22  15

Viscosity at 100 °C (mm2 s-1)

 3.2  3.6  3.4  4.1  3.6

Geared to purpose: Polyglycol base oils tailored for testing

Polyglycol (also known as PAG) base oils are available in a wide range of viscosity grades and can be matched with different additive packages to allow them to be precisely tailored to the evolving needs of EV drive fluids. To explore the capabilities of PAG base oils in terms of properties that are relevant to e-mobility, Clariant synthesized a small series of polyglycols with different chemical structures and properties, and subjected them to a series of tests.

The tests showed that Clariant’s synthetic PAG base oils (notably Polyglycol E04 E and Polyglycol E03 A) largely outperformed a polyalphaolefin (PAO) benchmark with respect to key parameters such as energy efficiency, friction coefficient, heat transfer, and ecotoxicity/sustainability.

Energy efficiency

Ball-on-disk tribometer

Heat transfer

relative heat transfer for turbulent flow conditions
Clariant Image Closed up macro ball bearing put into yellow tran 2021

Time to change gear and steer for clear benefits

Clariant’s polyglycol base oils offer an array of beneficial capabilities that make them ideally suited for use in EV fluids such as reduction gear oil. The tests carried out by the company provide a strong evidence base for their performance characteristics.  

The current relatively flexible situation regarding OEM standards and gear design offers scope for innovation in EV drive fluids. Ultimately, only highly efficient EV drivetrains supported by high-performance lubricants are capable of delivering the longer ranges that customers want and that EV manufacturers need in order to position their products in the market.

The race for electric mobility has only started. Don‘t miss out on it! The current challenges in energy efficiency and thermal management offers scope for innovation in EV drive fluids. Clariant is currently looking for partners to continue the development of innovative lubricants containing PAG base oils and bring new solutions to the market that would make electric mobility more efficient. Join us in our efforts to shape the future of electric mobility and specialty lubricants.

How can we help you formulate EV fluids?
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