Mercedes-Benz is working on a mid-cycle update for its M-Class SUV and word on the street is that the update will see a plug-in hybrid model added to the lineup. Mercedes has already revealed its first plug-in hybrid in the form of the S-Class-based S500 Plug-In Hybrid, which is due for the 2015 model year, and a prototype for a C-Class plug-in hybrid has already been spotted.

Green Car Reports is now reporting that an M-Class plug-in hybrid will arrive in showrooms about the same time as the C-Class plug-in hybrid, most likely in the fall of 2015, making it a 2016 model. This is about when we’re expecting the updated M-Class to be launched, so the M-Class plug-in hybrid’s arrival may be timed to coincide with the arrival of the updated M-Class range.    

The vehicle will go head-to-head with plug-in hybrid SUVs from Audi (Q7), BMW (X5), Land Rover (Range Rover) and Volvo (XC90). Tesla should have its all-electric Model X crossover at this point, too.

It’s not clear if Mercedes will go with a four-cylinder or V-6 for the internal combustion component of the new M-Class plug-in hybrid, but we can expect the vehicle to have an all-electric range of about 20 miles and fuel economy in excess of 50 mpg when using its available driving modes. These should include the same modes found in the S500 Plug-In Hybrid: HYBRID (mix of power sources), E-MODE (electric power only), E-SAVE (fully charged battery is reserved to be able to drive on electric power alone later) and CHARGE (battery is charged while driving).

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