New York Auto Show: 2013 Mercedes-Benz GL-Class Introduced on Wednesday, April 4: Mercedes GL-Class. The nation's best-selling, maxi-sized luxury S.U.V., refreshed to keep Cadillac Escalades and Range Rovers at bay. Beginning Sept. 1, GL buyers will begin bulldozing through a mall parking lot near you. What they said: Setting a high bar for mixed auto-show metaphors, Joachim Schmidt, Mercedes's sales and marketing chief, said the GL "may be built like a German castle, but it moves like Jagger." So cued, a brass band strolled in playing an oompah version of that infernally catchy Maroon 5 number. What they didn't say: Executives claimed an 18-percent fuel economy gain for the new GL450, but it's worth wondering if burly V-8 S.U.V."s remain vulnerable to spiking fuel prices. That may not trouble the GL buyer much, though. The German brand's ubiquitous biturbo, direct-injection V-8 engine replaces the old free-breathing eight. That 4.6-liter engine makes 406 horses in the GL450 and 429 in the GL550. A 240-horsepower diesel goes tick-tock, discreetly, in the GL350 Bluetec. Brand representatives said prices should not differ greatly from the outgoing model; figure on a base price around $63,000 for the GL450, roughly $1,000 less for the diesel model and about $85,000 for the GL550, meaning a stuffed GL could bust into the six figures. How very Range Rover. Flashing its three-pointed star like a Black Forest sheriff's badge, the GL is larger and more luxurious than its predecessor, but still as conforming and manicured as a suburban lawn.