Infiniti QX80 vs Mercedes-Benz GLB-Class: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Mercedes-Benz GLB-Class burns about $2,700 of fuel annually against $4,200 for the Infiniti QX80. That $1,500 yearly gap compounds to roughly $7,500 over five years and $12,000 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 Mercedes-Benz GLB-Class leads in both cycles — 25 mpg city and 33 mpg highway against 16 and 20 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Infiniti QX80 is recorded with 4 distinct engine configurations (SIDI, SIDI; MDPV, SIDI; MDPV (Curb Weight >6000 lbs)), the Mercedes-Benz GLB-Class with 2 (SIDI; Mild Hybrid, SIDI). Across 30 recorded Infiniti QX80 configurations and 20 for the Mercedes-Benz GLB-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 Infiniti QX80 is offered with 4-Wheel Drive, Rear-Wheel Drive, the Mercedes-Benz GLB-Class with Front-Wheel Drive, 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 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 GLB-Class emits 311 g/mile of CO2 versus 504 g/mile for the Infiniti QX80. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.