Following the updates to the ML and GLK, Mercedes-Benz has now announced the upgrades to the 2013 GL full-size, seven-passenger SUV. The GL's engine lineup goes all-turbo for 2013, with two versions of the company's 4.7-liter twin-turbo direct-injection V-8, and an updated 3.0-liter turbodiesel V-6.

As has been Mercedes' practice for the last several years, nomenclature on models stays consistent while actual engine displacement sometimes changes year-to-year. That being the case, both the GL450 and GL550 are 4.7 liter, while the GL350 Bluetec is a 3.0-liter. The GL450 features a lightly-turbocharged version of the 4.7 producing 362 hp and 406 lb-ft of torque, while the GL550 pumps up the boost for a beefier output of 429 hp and 516 lb-ft of torque, incidentally the same as the new SL 550 roadster and S 550 sedan. The 2013 GL also gets the ML's updated Bluetec diesel, for an output of 240 hp and 455 lb-ft of torque. All three models are rated for a maximum towing capacity of 7500 pounds, properly-equipped.

As expected for a top-of-the-line Mercedes, there is a dizzying array of standard and optional equipment available, with a big emphasis on safety, with a myriad of electronically-assisted safety systems on the new GL. Standard for 2013 are Collision Prevention Assist, Attention Assist, and Crosswind Stabilization. Optional on the GL450 and GL350 Bluetec, and standard on the GL550 is Distronic Plus cruise control, with Pre-Safe autonomous braking, and active lane-keeping assist and active blind spot assist included.

LED front running lights and taillights are standard across-the-board, with bi-xenon HID headlights with active curve illumination optional on the GL450 and GL350, and standard on the GL550. The GL450 and GL350 get standard 19-inch wheels with optional 20-inchers, while the GL550 gets standard 21-inch wheels.

And although low-range four-wheel drive is becoming an increasingly scarce feature in the SUV segment, the GL still offers it as an option with the On-and-Off-Road Package, which features a skidplate, two-speed transfer case, longitudinal differential lock, and a beefed-up version of the standard Airmatic suspension delivering a maximum ground clearance of 12 inches and a wading depth of 23.6 inches. This package is available on the GL450 and GL550.

Moving to the interior, the GL features standard MB Tex upholstery, heated 8-way power front seats, a power tilt/sliding glass sunroof, and a power liftgate for convenience. But most of the real goodies are offered in the two optional Premium packages. The Premium 1 package includes an iPod/MP3 interface, hard-drive navigation with voice control, satellite radio, power folding mirrors, multi-color ambient lighting, and 10-way heated power front seats with memory.

The Premium 2 package adds a harman/kardon Logic7 surround-sound system, Keyless-Go, a lockable rear storage compartment, and soft-close doors. Available a la carte, among many features, are a rear seat entertainment system, heated rear seats, several of Mercedes signature designo custom interior themes, illuminated running boards, and a towing package.

If you don't want to bother with cherry-picking your options, and budget isn't an issue, just go for the GL550, which includes most of the equipment of the two Premium packages standard.

Pricing was not announced for the 2013 models, but for reference, the 2012 GL350 Bluetec starts at $62,445 including destination, the GL450 at $63,445, and the high-roller GL550 at $86,175. The 2013 GL models are scheduled to go on-sale in the U.S. starting in September 2012.