Buick Enclave vs Mercedes-Benz GLS-Class: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Buick Enclave burns about $2,650 of fuel annually against $3,600 for the Mercedes-Benz GLS-Class. That $950 yearly gap compounds to roughly $4,750 over five years and $7,600 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 versus highway split: the Mercedes-Benz GLS-Class is the stronger commuter at 20 mpg city, while the Buick Enclave pulls ahead on the interstate at 27 mpg highway. If most of your driving is stop-and-go traffic the city figure is the one to weigh; for long-distance highway mileage the reverse is true, and the two vehicles effectively swap places depending on how you drive.

Powertrain choice: the Buick Enclave is recorded with 1 distinct engine configuration (SIDI), the Mercedes-Benz GLS-Class with 2 (SIDI; Mild Hybrid, SIDI). Across 26 recorded Buick Enclave configurations and 35 for the Mercedes-Benz GLS-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 Buick Enclave is offered with All-Wheel Drive, Front-Wheel Drive, the Mercedes-Benz GLS-Class with All-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 Standard 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 Buick Enclave emits 387 g/mile of CO2 versus 414 g/mile for the Mercedes-Benz GLS-Class. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.