Targeting eAxle efficiency through additives

eAxle efficiency can be enhanced using three related lubricant levers: viscosity, cooling and traction. Low viscosity fluids contain smaller molecules that require less energy to be moved around and have lower churning losses. Smaller fluid molecules absorb less heat overall but do so faster than larger molecules, which improves cooling and operating efficiency. Low traction fluids comprise ‘smoother’ molecules that move past each other more easily, minimizing energy losses. However, although closely related to friction and cooling performance, manipulating viscosity alone does not guarantee efficiency. 

Highly linear synthetic fluids with uniform molecular weight and polymer chains with limited branching can deliver impressive cooling, traction and efficiency benefits. However, their use introduces additional lubrication challenges because linear synthetics form particularly thin tribofilms. Additives can unlock the full efficiency benefits of these advanced fluids for OEMs, but they must be applied with understanding and skill.

This article explores that extending Electric Vehicle (EV) range by focusing on fluid viscosity alone can lead to dead ends where efficiency is not improved and durability is compromised. Customized additive support for specific combinations of fluid and OEM hardware design is the most direct route to optimized efficiency. 
 

This article was published in the October 2023 edition of Transmission Technology International