Spied: 2013 Mercedes S-Class and GL-Class

Spies have caught the next-generation Mercedes S-Class luxury sedan undergoing final cold-weather testing in Northern Sweden, wearing minimal disguise.

Gone are the prototype bolt-on rear lights, thick coating on the side profile, and fake bodypanels, revealing more details like the LED rear lights, chrome grille, and front bumper with curvy fog-light surrounds.

Initially, it was thought that the S-Class would borrow styling from the F125 and F800 concepts, but the grille is similar to the F700 Research Vehicle that was first unveiled back in 2007.

Engine options are expected to mirror the current model, albeit with some updates and tweaks that will improve fuel efficiency and lower emissions. These should include a 250 CDI, a S350 CDI, a S300 BlueTec diesel-hybrid, a S400 BlueTec petrol-hybrid, the S500 (aka S550), S600, S63 AMG and S65 AMG.

Unconfirmed reports hint that Mercedes wants a host of hybrid variants, including a plug-in hybrid S500 Vision Concept that is powered by a 3.0 litre V6 petrol and a 60PS (44kW) electric motor. This allows for a combined fuel economy figure of 78mpg (3.0l/100km).

Like its predecessor, the new S-Class with arrive with a shed fall of new technology, including a couple of forward-facing cameras integrated into the rear-view mirror. The current forward radar system will also be modified to allow the debut of Magic Ride Control, a damping system that Mercedes anticipates will reduce body movement by 50%, in addition to the system being able to see vulnerable pedestrians. A low-speed adaptive cruise control that overtakes the steering in certain situations will also feature.

Following the unveiling of the S-Class sedan, we expect a long-wheelbase sedan and a coupé to launch later. These will also be joined by a cabriolet and a pair of ultra-luxurious Pullman models that replaces the Maybach brand.

2013 Mercedes GL-Class:

Spy shooters have caught the second-generation Mercedes GL-Class completely undisguised on a photoshoot in the U.S. Using telescopic lenses, we believe the model captured here is the GL63 AMG, thanks to large air-intakes, 20” AMG alloy wheels, and a rear roof spoiler.

The styling of the new GL follows the rest of the Mercedes line-up, with large wraparound headlights, two chrome grille, commanding design lines, and a softer, rounded silhouette.

Based on the smaller unibody M-Class, we expect the engine line-up to be adopted from the aforementioned model. The range-topping GL63 AMG will be equipped with a twin-turbo 5.5 litre V8 petrol, that will produce 518bhp (525PS/386kW) and 700Nm (516lb-ft) of torque. As the M-Class is lighter than its predecessor, we expect the diesel GL350 CDI to emit less than 200g/km.

Look out for a debut at next month's New York International Auto Show, before it hits the market in Summer 2013.

Via WorldCarFans.com & AutoEvolution.com