BMW 7 Series vs Lexus IS: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the BMW 7 Series burns about $2,700 of fuel annually against $2,900 for the Lexus IS. That $200 yearly gap compounds to roughly $1,000 over five years and $1,600 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 BMW 7 Series is the stronger commuter at 25 mpg city, while the Lexus IS pulls ahead on the interstate at 32 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 7 Series is recorded with 4 distinct engine configurations (SIDI & PFI; Mild Hybrid, SIDI; Mild Hybrid, SIDI; PHEV), the Lexus IS with 2 (SIDI & PFI, SIDI). Across 69 recorded BMW 7 Series configurations and 52 for the Lexus IS, 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 7 Series is offered with Rear-Wheel Drive, All-Wheel Drive, the Lexus IS with All-Wheel Drive, Rear-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 Large Cars and Compact 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 BMW 7 Series emits 130 g/mile of CO2 versus 345 g/mile for the Lexus IS. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.