Lexus TX vs Porsche Cayenne: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Lexus TX burns about $2,600 of fuel annually against $3,300 for the Porsche Cayenne. That $700 yearly gap compounds to roughly $3,500 over five years and $5,600 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 Lexus TX is the stronger commuter at 29 mpg city, while the Porsche Cayenne pulls ahead on the interstate at 29 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 Lexus TX is recorded with 3 distinct engine configurations (SIDI & PFI, SIDI & PFI; Hybrid, SIDI & PFI; PHEV), the Porsche Cayenne with 4 (SIDI, SIDI; PHEV, 4.0). Across 10 recorded Lexus TX configurations and 97 for the Porsche Cayenne, 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 Lexus TX is offered with All-Wheel Drive, Front-Wheel Drive, the Porsche Cayenne with 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 Standard Sport Utility Vehicle 4WD and Standard Sport Utility Vehicle 4WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Lexus TX emits 120 g/mile of CO2 versus 174 g/mile for the Porsche Cayenne. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.