BMW X6 vs Mercedes-Benz GLA-Class: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Mercedes-Benz GLA-Class burns about $2,600 of fuel annually against $3,150 for the BMW X6. That $550 yearly gap compounds to roughly $2,750 over five years and $4,400 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.

City and highway economy: the Mercedes-Benz GLA-Class leads in both cycles — 26 mpg city and 34 mpg highway against 23 and 27 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the BMW X6 is recorded with 4 distinct engine configurations (SIDI; Mild Hybrid, SIDI & PFI; Mild Hybrid, SIDI), the Mercedes-Benz GLA-Class with 3 (SIDI; Mild Hybrid, SIDI, SIDI; FFV). Across 47 recorded BMW X6 configurations and 43 for the Mercedes-Benz GLA-Class, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.

Drivetrain and class: the BMW X6 is offered with All-Wheel Drive, Rear-Wheel Drive, the Mercedes-Benz GLA-Class with All-Wheel Drive, Front-Wheel Drive, 4-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Standard Sport Utility Vehicle 4WD and Small Sport Utility Vehicle 4WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Mercedes-Benz GLA-Class emits 306 g/mile of CO2 versus 359 g/mile for the BMW X6. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.