Audi A5 vs Subaru Legacy: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Subaru Legacy burns about $2,050 of fuel annually against $2,550 for the Audi A5. 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 Subaru Legacy is the stronger commuter at 27 mpg city, while the Audi A5 pulls ahead on the interstate at 36 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 Audi A5 is recorded with 4 distinct engine configurations (SIDI;, SIDI, SIDI; Mild Hybrid), the Subaru Legacy with 3 (SIDI, 2.5, 3.6). Across 40 recorded Audi A5 configurations and 16 for the Subaru Legacy, 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 A5 is offered with All-Wheel Drive, the Subaru Legacy 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 Subcompact Cars and Midsize Cars respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Subaru Legacy emits 295 g/mile of CO2 versus 300 g/mile for the Audi A5. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.