In this review paper, new developments in thermal management fluids have been described to help promote the high-performance cooling system on electrical batteries, motors, and power electronics. The major section of this paper will be focused on the most important progress of automotive lubrication in the areas of energy conversion effectiveness, driveline trustworthiness, cooling system design and thermal management control. The major goal of this paper is to underline the future electrification development trends and the required lubricants for advanced Hybrid/EV vehicles. Coming research activities in innovative driveline fluids will be focused on minimizing friction loss and maximizing hybrid component durability. This review paper will provide with global insights on future automotive electrification growth trends with respect to innovative driveline lubricants and thermal cooling liquids used in Hybrid/EV vehicles. Automotive industries have asked for the implementation of specialized automotive lubricants or driveline fluids to allow for appropriate thermal cooling specifications, present bearing protection, ensure corrosion protection, and offer oxidation and sludge control. The introduction of electrification components has been targeted for energy efficiency and long-term durability. This leads to the addition of electrical and thermal properties, which must be taken into account on top of conventional lubricant properties. In many HEV or EV advanced system designs, automotive lubricants such as drivetrain fluids or thermal coolants comes into contact with the integrated electric motor (e-motor) and thermal management devices. Advanced propulsion systems rising from global guidelines are meant to improve vehicle fuel efficiency and minimize pollution emissions from transportation vehicles. This industrial impact on global development trend into automotive electrification designs has created an emerging technology for new propulsion systems such as hybrid electrical vehicles (HEV) or electrical vehicles (EV). Global automotive industries have recently switched development trends from the traditional powertrain mechanical components into the digital transformation of the electrification components in advanced propulsion vehicles.

3Koehler Instrument Company, New York, NY, United States.2MATRILUB Materials Tribology Lubrication, Rochester Hills, MI, United States.1Innovation Technology Consulting, Rochester Hills, MI, United States.

What are hybrid vehicles