Aston Martin DB11 vs Porsche 911: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Porsche 911 burns about $3,050 of fuel annually against $3,800 for the Aston Martin DB11. That $750 yearly gap compounds to roughly $3,750 over five years and $6,000 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 Porsche 911 leads in both cycles — 22 mpg city and 30 mpg highway against 18 and 24 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Aston Martin DB11 is recorded with 3 distinct engine configurations (SIDI, 5.2, 4.0), the Porsche 911 with 1 (SIDI). Across 13 recorded Aston Martin DB11 configurations and 361 for the Porsche 911, 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 Aston Martin DB11 is offered with Rear-Wheel Drive, the Porsche 911 with Rear-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 Minicompact Cars and Minicompact 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 Porsche 911 emits 355 g/mile of CO2 versus 431 g/mile for the Aston Martin DB11. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.