Why BMW XM Lacks Plug-in Hybrid Feature

BMW XM: No Engine-Charging Feature for PHEV

CarBuzz had an opportunity recently to try the 2023 BMW XM at its global introduction event, where though we can not discuss how it drives just now, we did ascertain that it is excluding a key function ordinarily found on most plug-in hybrids: powering the battery with the engine.

The M Hybrid switch situated in the middle console allows motorists to opt between three alternate settings: Hybrid, Electric, as well as eControl. Hybrid and Electric are quite discernible; the former unites the electric motor with the gasoline engine, while the latter deactivates the motor and uses electricity alone for approximately 30 miles. This is just like various other PHEVs.

BMW’s eControl mode is where the differentiation really begins. Other PHEVs available offer both a choice to keep the charge level or use the engine to produce electricity back into the battery, while the XM possesses the capability just to maintain a steady power supply.

When enquired about the absence of a charge option, a BMW representative affirmed “it would adversely affect the fuel economy,” adding that “running the engine to charge the battery is wasteful.”

It is clear BMW is aware of the unfavorable effects on fuel economy of running a PHEV engine for battery recharging. This can be attributed to basic physics, wherein it is more efficient to use the engine when driving, as opposed to just charging the battery. Though car makers continue to offer this functionality, so that drivers can have a fully charged battery after a prolonged period on the street, the true extent of its utilization remains unknown.

Despite the fact that it is not possible to employ the XM’s motor to recharge its battery, energy recuperation can take place by pushing down on the brakes, coasting or via two distinct regeneration settings: Normal and Maximum. In theory, a preferable charge level (SOC) could be accomplished with an active drive – especially driving downhill. Here is where the heavy weight of 6,063 lbs could be advantageous, as the sheer momentum going downwards may put back considerable energy into the engines and battery cells.

Despite the fact that the XM is not the first BMW PHEV to lack a recharge on-the-go feature – with other models such as the X5 Hybrid and the X2 Hybrid (not sold in the US) only providing an option to maintain the state of charge, not increase it – a spokesperson for the company said: “It would hurt our fuel economy ratings if we offered that feature.”

It may be possible that there is indeed some credence to the idea that cars formerly produced with Hyundai Motor Group had an option to charge while in motion, however, it is no longer a part of their designs. Audi Q5 PHEV continues to incorporate both a charge mode and charge hold mode as do vehicles made by Toyota and Volvo. It should be noted though that these car makers’ PHEVs are certainly not outfitted with a twin-turbo 4.4 liter V8 engine – which is what makes them different.