BMW was a pioneer in the EV segment with range-extending engines. The i3 REX debuted over a decade ago, featuring an optional two-cylinder engine. Borrowed from the Motorrad division, the compact 647-cc gas engine was adapted to serve as a generator to recharge the battery. It was a one-off solution, as the packaging was never replicated in another model.
However, a new report from Autocar suggests that the range-extending engine could make a comeback. The British publication cites sources familiar with BMW’s plans, pointing to a new system co-developed with supplier ZF. The technology is reportedly intended for SUVs and could debut in the next-generation X5 (pictured here), codenamed “G65.”
The tech may also be used in the next-generation X7, the “G67.” The three-row SUV is scheduled to launch in the second half of 2027. Even the current X3, known internally as “G45,” is believed to be a candidate for REX treatment, although this is unlikely to happen until its mid-cycle facelift. The LCI is expected to arrive in late 2028.
The new range-extending gas engine would run only at its optimal rpm to maximize efficiency. It could be paired with BMW’s next-generation batteries, especially considering the all-electric iX5 will use the Gen6 pack debuting in the Neue Klasse iX3 later this year. These cylindrical cells will offer 20% higher energy density and a 30% increase in range compared to today’s prismatic batteries. Combined with the REX, this should virtually eliminate range anxiety, even in large SUVs like the X5 and X7.
The X5 is shaping up to have an exceptionally diverse powertrain lineup: gasoline, diesel, plug-in hybrid, battery electric, hydrogen fuel cell, and now this rumored range-extender pairing a gas engine with batteries. BMW is unlikely to offer all versions globally; instead, it will tailor availability based on regional demand.
For example, range extenders are gaining popularity in China. Volkswagen’s revived Scout brand will introduce the technology in the U.S. on the upcoming Terra pickup and Harvester SUV. VW’s core brand also plans to launch range-extending EVs in China and potentially other regions. Its upcoming Scalable Systems Platform (SSP) will support EVs equipped with a combustion engine that acts as a generator.
It remains unclear how much an X5 with a range extender would cost, though it’s likely to be priced between the plug-in hybrid and the fully electric iX5.