Even with the vast array of technology at its disposal--including an eight-speed automatic, some lightweight materials, and an entire model dedicated to fuel savings, the gas-and-battery LS 600h L hybrid--the 2013 Lexus LS still only manages the fuel economy of a big crossover SUV.
In base form, the Lexus LS 460 with rear-wheel drive is rated by the EPA at 16 miles per gallon city, 24 miles per gallon highway, for a combined rating of 19 mpg. That's for either the standard- or long-wheelbase edition, and they're figures close to those you'd earn in Toyota's Highlander. Adding all-wheel drive drops by one mile per gallon the highway gas mileage number and the combined rating.
The LS 460 does encourage drivers to behave more responsibly with an ECO light on the gauges. It meters fuel usage, and blinks rapidly when acceleration pushes the sedan into lower-economy modes.
The LS 600h L hybrid, meanwhile, earns a rating of 19 mpg city, 23 mpg highway, and 20 mpg combined—solid ratings for the class, but in our experience, somewhat difficult to replicate. It does attempt to coach drivers to economize with a more detailed display that shows hybrid-driving modes in the place of the tachometer, except when Sport mode is selected.