Audi SQ8 vs BMW X4: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the BMW X4 burns about $3,050 of fuel annually against $4,450 for the Audi SQ8. That $1,400 yearly gap compounds to roughly $7,000 over five years and $11,200 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 BMW X4 leads in both cycles — 23 mpg city and 29 mpg highway against 15 and 21 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Audi SQ8 is recorded with 1 distinct engine configuration (SIDI), the BMW X4 with 2 (SIDI, SIDI; Mild Hybrid). Across 8 recorded Audi SQ8 configurations and 35 for the BMW X4, 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 Audi SQ8 is offered with All-Wheel Drive, the BMW X4 with All-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 BMW X4 emits 351 g/mile of CO2 versus 518 g/mile for the Audi SQ8. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.