To put this in a positive light, in real-world driving we've managed to meet or beat those ratings across a couple of drives--a feat we can't claim in many new vehicles.
The 2012 GX 460 is in many respects an homage to older truck-based luxury SUV designs, and in fuel efficiency there's no real exception. Even with a new engine, which brought some mileage improvements, the GX stands at an EPA-rated 15 mpg city, 20 highway. At that, it's still quite the guzzler, and near the bottom of the scale among all vehicles. And to add to the impact of the fuel bills, premium (91 octane or higher) gasoline is required.