Our spy photographers have caught the next-generation Mercedes-Benz ML SUV out testing in advance of its debut this year.

The photos are the clearest sneak-peek we've had for the popular Benz luxury SUV. Current ML350 owners will definitely recognize the new ML as related, but there are a few changes. A larger grille, revised front fascia, and teardrop-like headlights are new, as is the reshaped hood.

The pre-production model shown here sports clean twin five-spoke wheels and similar side mirrors with stylized turn signal indicators. The ML's profile -- complete with a thick C-pillar and a wraparound rear windshield appearance -- is not significantly changed, though there is a new character line that ends at the front wheel wells. Probably the most noticeable difference is with the redone taillights, which are much bigger than before and make a cleaner cut line for the rear bumper.

One of the reasons the current ML has become so popular in Mercedes-Benz's lineup (behind only the C- and E-class cars in sales) is the powertrain variety. The volume model for the upcoming ML will likely be powered by a version of the 302-horsepower 3.5-liter V-6 in the 2012 SLK. That model, the ML350, could remain the only ML in the U.S. with a base price under $50,000. A diesel, V-8, and AMG model are no doubt on the way, not to mention the possibility of a plug-in hybrid.

Considering the fact that the ML350, ML350 BlueTec, ML550, and ML63 AMG all trail their respective BMW X5 competitive models in fuel economy, expect EPA numbers on the ML to increase. The 2011 ML350 with all-wheel-drive is rated 15/20 mpg city/highway, while the 2011 ML550 gets 13/18 mpg. Keep your eyes on MotorTrend.com as we get more information on the next-generation Mercedes-Benz ML.