Audi TT vs Lexus IS: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Audi TT burns about $2,350 of fuel annually against $2,900 for the Lexus IS. 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 versus highway split: the Audi TT is the stronger commuter at 23 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 Audi TT is recorded with 1 distinct engine configuration (SIDI), the Lexus IS with 2 (SIDI & PFI, SIDI). Across 12 recorded Audi TT 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 Audi TT is offered with 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 Subcompact 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 Audi TT emits 340 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.