UK magazine What Car? has compared the real-world gas mileage of five luxury sports sedans and found the Lexus IS 300h to deliver the best results.
The IS 300h, which is officially rated at 64.2 mpg in Britain, returned 59.6 mpg in the What Car? test. The Mercedes C220 CDI, despite having an official rating of 68.9 mpg, finished second with 57.5 real-world mpg.