Lexus aimed to improve fuel efficiency without sacrificing performance with the gen-2 2013 Lexus GS 450h hybrid.

Barely a month after lifting the covers on the second-generation of its mid-luxury sedan Lexus is back and charging into the Frankfurt Motor Show with the updated 2013 Lexus GS 450h hybrid.

During a Pebble Beach preview, Toyota Motor Co. CEO Akio Toyoda underscored the importance of the Lexus GS line.  Though it might not be the luxury brand’s flagship – a space reserved for the bigger LS – the GS has been as close as it comes to the heart and soul of the Lexus division.

The GS 350 shown last month is a fair bit sportier and more refined than the original sedan.  And the Lexus GS 450h is no different there.  But there’s been a bit of a shift in its mission.  The original hybrid put the emphasis on performance and was actually a bit quicker than the standard-issue GS sedan.  This time, Lexus is focusing on fuel-efficiency and claims the GS 450h delivers a 30% improvement over the gas-powered model.

To improve the green bona fides of the Lexus GS 450h engineers took a number of steps to improve its 3.5-liter V-6, which already took the unusual step of using a combination of port and direct fuel-injection.  For 2013, the engine’s compression ratio is upgraded from 10.5:1

The 2013 version of the GS 450h engine has also been modified to run on the so-called Atkinson Cycle.  That means, among other things, that its intake valves stay open longer for improved efficiency.  Torque tends to drop but that can be made up by careful application of the GS 450h hybrid drive.

That side of the engine, which uses an electric motor linked through a continuously variable transmission, has also been updated in the 2013 Lexus GS 450h.  The new version of the hybrid sedan features an updated control system and for those who liked the sporty side of the old model they can choose between Eco, EV, Sport S and Sport+ modes.

The electric motor itself is said to experience less friction, thus improving its efficiency.  On the other hand, it is, for 2013, more effective at recapturing energy normally lost during braking and coasting.

For 2013, the GS 450h delivers 338 horsepower, about 2 less than before.  Lexus isn’t offering performance numbers but it is likely to be slightly slower in Eco mode and could actually match or exceed the old 5.6-second 0 to 60 times of the old model.

One reason is that Lexus claims to have made other efficiency improvements to the mid-lux sedan.  There’s the new S-Flow climate control system and even the audiophile sound system adopts new lighter, more efficient speakers.

“This is the first car to wear the new face of Lexus,” CEO Toyoda said last month of the GS 350 and the hybrid version looks very much the same but for badging and some other subtleties, such as the tri-lamp headlights, hidden exhaust pipes and, inside, “renewable” bamboo-trimmed steering wheel and upgraded hybrid system monitor.

By delivering big gains in mileage while also helping add some oomph to the 2013 GS 450h performance Lexus is hoping the new hybrid will be taken a bit more seriously this time ‘round.