BYD and ExxonMobil deepen their PHEV alliance

BYD and ExxonMobil signed a long-term strategic cooperation memorandum on 26 January, formalising an extension of their existing partnership focused on hybrid vehicle technology and specialised lubricants. The agreement, signed at BYD’s Shenzhen headquarters, establishes a framework for continued joint research, customised product development and industrial application of hybrid technologies. 

Neither company has disclosed financial terms, investment figures or specific product timelines. The partnership builds on previous collaboration that yielded, among other things, a customised engine oil product launched in 2025, specifically engineered for plug-in hybrid electric vehicles (PHEVs). The lubricant is intended to address operating challenges that are unique to PHEVs—for example, frequent cold starts and short-distance operation cycles. 

The renewed framework creates a mechanism through which the two companies can improve their coordination during the product development and validation processes. While ExxonMobil leans on its global production and logistics networks specifically for lubricants and adjacent products, BYD offers its expertise in hybrid engine technology and vehicle production. The MoU also includes language related to the exploration of new materials applications, although there is little by way of concrete information on this front. 

For the last few years, BYD has been distinguished as the world’s largest producer of PHEVs, selling 2,288,709 units in 2025. The automaker commanded a 19.3% market share in this segment, and seven of the ten best-selling PHEVs last year were BYD models. It makes sense, then, that Exxonmobil—a company in an industry that has in various forms attempted to turn back the dial towards fossil fuel dependency—would partner with BYD to strengthen a technology that stops short of full electrification. 

However, it goes beyond a broad opposition towards zero-emission technologies: ExxonMobil’s partnership with BYD  on e-fluids for cooling high-performance e-motors and gears, alongside specialised lubricants for hybrid powertrains, allows the company to stay relevant in automotive supply chains even in the event that battery-electric vehicles eliminate traditional internal combustion engines entirely.

Both companies have indicated that they will participate in standards-related work for hybrid and new energy technologies, although the memorandum specified neither target regulatory bodies nor implementation schedules.