BMW 4 Series vs Volvo S90: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the BMW 4 Series burns about $2,450 of fuel annually against $2,550 for the Volvo S90. That $100 yearly gap compounds to roughly $500 over five years and $800 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 Volvo S90 is the stronger commuter at 28 mpg city, while the BMW 4 Series 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 BMW 4 Series is recorded with 4 distinct engine configurations (SIDI & PFI; Mild Hybrid, SIDI, SIDI; Mild Hybrid), the Volvo S90 with 4 (SIDI; Mild Hybrid, SIDI; PHEV, 2.0). Across 160 recorded BMW 4 Series configurations and 23 for the Volvo S90, 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 4 Series is offered with Rear-Wheel Drive, All-Wheel Drive, the Volvo S90 with Front-Wheel Drive, 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 Compact 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 Volvo S90 emits 110 g/mile of CO2 versus 285 g/mile for the BMW 4 Series. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.