BMW i5 vs Mercedes-Benz CLA-Class: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Mercedes-Benz CLA-Class burns about $600 of fuel annually against $650 for the BMW i5. That $50 yearly gap compounds to roughly $250 over five years and $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 CLA-Class leads in both cycles — 127 mpg city and 124 mpg highway against 120 and 113 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the BMW i5 is recorded with no distinct engine configurations, the Mercedes-Benz CLA-Class with 3 (SIDI; Mild Hybrid, SIDI, SIDI; FFV). Across 30 recorded BMW i5 configurations and 55 for the Mercedes-Benz CLA-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 i5 is offered with All-Wheel Drive, Rear-Wheel Drive, 4-Wheel Drive, the Mercedes-Benz CLA-Class with All-Wheel Drive, Rear-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 Compact Cars and Compact Cars respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.