Ford Mustang vs Kia K4: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Kia K4 burns about $1,800 of fuel annually against $2,350 for the Ford Mustang. That $550 yearly gap compounds to roughly $2,750 over five years and $4,400 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 Kia K4 leads in both cycles — 30 mpg city and 40 mpg highway against 22 and 33 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Ford Mustang is recorded with 4 distinct engine configurations (5.2, 5.0, SIDI & PFI), the Kia K4 with 3 (SIDI, 2.0, with DMS). Across 133 recorded Ford Mustang configurations and 8 for the Kia K4, 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 Ford Mustang is offered with Rear-Wheel Drive, the Kia K4 with 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 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 Kia K4 emits 264 g/mile of CO2 versus 341 g/mile for the Ford Mustang. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.