Lexus RX vs Mercedes-Benz GLA-Class: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Lexus RX burns about $2,100 of fuel annually against $2,600 for the Mercedes-Benz GLA-Class. 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 versus highway split: the Lexus RX is the stronger commuter at 37 mpg city, while the Mercedes-Benz GLA-Class pulls ahead on the interstate at 34 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 Lexus RX is recorded with 4 distinct engine configurations (SIDI & PFI, SIDI & PFI; Hybrid, SIDI & PFI; PHEV), the Mercedes-Benz GLA-Class with 3 (SIDI; Mild Hybrid, SIDI, SIDI; FFV). Across 59 recorded Lexus RX configurations and 43 for the Mercedes-Benz GLA-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 Lexus RX is offered with Front-Wheel Drive, All-Wheel Drive, the Mercedes-Benz GLA-Class with All-Wheel Drive, Front-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 Small 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 Lexus RX emits 89 g/mile of CO2 versus 306 g/mile for the Mercedes-Benz GLA-Class. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.