The GS 450h doesn't get a power boost to go with its new mean mug. (In fact, the new 338-horsepower, Atkinson cycle V-6-based Hybrid Synergy Drive system is down two ponies from the current generation.) What Lexus is expecting is a 30 percent bump in fuel economy when the sedan finishes EPA testing. The
2009 GS 450h rolled a combined 23.2 mpg when we tested it, so we're guessing the 2013 will reach a combined 30.