Cadillac XT6 vs GMC Acadia: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the GMC Acadia burns about $2,450 of fuel annually against $2,950 for the Cadillac XT6. That $500 yearly gap compounds to roughly $2,500 over five years and $4,000 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 GMC Acadia leads in both cycles — 22 mpg city and 29 mpg highway against 21 and 27 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Cadillac XT6 is recorded with 1 distinct engine configuration (SIDI), the GMC Acadia with 1 (SIDI). Across 22 recorded Cadillac XT6 configurations and 44 for the GMC Acadia, 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 Cadillac XT6 is offered with Front-Wheel Drive, All-Wheel Drive, the GMC Acadia with All-Wheel Drive, Front-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 Small Sport Utility Vehicle 2WD and Standard Sport Utility Vehicle 2WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the GMC Acadia emits 349 g/mile of CO2 versus 386 g/mile for the Cadillac XT6. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.