We were recently given the opportunity to take the 2009 Mercedes-Benz GL320 BlueTEC on a long-distance road trip from San Francisco to Los Angeles and back. The powerplant in question is a 3.0-L turbodiesel V-6 that outputs 210 horsepower and a beefy 398 pound-feet of torque. The engine sends its power through a seven-speed adaptive automatic transmission to Mercedes-Benz's 4MATIC permanent all-wheel drive system. Keeping the diesel's emissions clean is an AdBlue injection system that scrubs up to 80 percent of NOx from the exhaust gases. Greenies will be happy to know that the BlueTEC diesel is also approved for use with B5 biodiesel. On the road, the 398 pound-feet of torque doesn't translate into neck-snapping acceleration. Perhaps this is because of the GL's immense weight; perhaps it's the turbo lagging; or maybe Mercedes has tuned some of the throttle response down to create more refined and fuel efficient acceleration.

We were recently given the opportunity to take the 2009 Mercedes-Benz GL320 BlueTEC on a long-distance road trip from San Francisco to Los Angeles and back. The powerplant in question is a 3.0-L turbodiesel V-6 that outputs 210 horsepower and a beefy 398 pound-feet of torque. The engine sends its power through a seven-speed adaptive automatic transmission to Mercedes-Benz's 4MATIC permanent all-wheel drive system. Keeping the diesel's emissions clean is an AdBlue injection system that scrubs up to 80 percent of NOx from the exhaust gases. Greenies will be happy to know that the BlueTEC diesel is also approved for use with B5 biodiesel. On the road, the 398 pound-feet of torque doesn't translate into neck-snapping acceleration. Perhaps this is because of the GL's immense weight; perhaps it's the turbo lagging; or maybe Mercedes has tuned some of the throttle response down to create more refined and fuel efficient acceleration.

Whatever the cause, the GL320 feels sluggish off of the line. Really putting your foot into the accelerator and waiting for the turbodiesel to build steam eventually results in that torquey diesel thrust that we're used to, but the acceleration is uneven and slightly unpredictable. Our GL320 was equipped with the optional Adaptive Damping System, which adds a Sport mode and a Comfort mode to the suspension's Default setting. The three modes felt noticeably different, with Sport mode transmitting a good deal of expansion joint harshness into the seat bottom and Comfort mode feeling floaty and vague. Speeding down Interstate 5, cruise control holding the SUV at a steady 75 mph, the GL's leather appointed cabin isolated its passenger from road and wind noise. The leather-trimmed seats were quite comfortable for the seven-plus hour trip, but the high seating position had us feeling like we were sitting on top of a vehicle rather than inside of one. The vague feedback through the steering and suspension made us feel even more isolated from the driving experience, but somehow we think that's the point of driving a vehicle this large.

On the bright side, the power steering was light and quite responsive to inputs. Fortunately, the GL320's cabin tech package was able to keep us entertained where the ride did not. Pod connectivity, a six-disc DVD/CD changer, and in-dash SD card reader join AM/FM/HD radio and Sirius satellite radio on the list of available sources. Because of our lack of passengers, neither the DVD playback option nor the dual-screen, seatback-mounted rear seat entertainment system got too much of a workout on this particular trip. All audio is routed through a Harmon/Kardon Logic7 surround sound system that sounds fantastic in the GL's quiet cabin. Pointing us in the right direction was the 6.5-inch full color navigation system with traffic. The 40GB hard drive that holds the system's map data reserves a 4GB Music Register for ripping audio files. As we reached our destination, the GL320's trip computer was reporting an astounding 26.3 miles per gallon for the trip. Okay, so 26.3 mpg isn't exactly "astounding," but when you consider that the GL is a huge seven-passenger SUV, we're grateful for every mile per gallon gained. Consider that that the gasoline-powered variants average 18 highway mpg, at best, and that the GL320 BlueTEC's V-6 generates more torque than the GL550's 5.4-L gasoline V-8, and the fuel economy advantage is even more impressive. 58,200 for a nicely equipped 2009 Mercedes-Benz GL320 BlueTEC. 6,600 P01 package, which includes almost every tech option available to the GL. 1,850 rear seat entertainment system.

After two generations and 12 years of wearing the same hard-edged blocky aesthetic that helped establish Mercedes-Benz in the seven-seater segment, the GLS debuted at the 2019 New York Auto Show with a softer, curvier, and more elegant presence. The all-new generation is bigger, more powerful, more advanced, and more premium; and it wears Mercedes' Sensual Purity design language with maturity. The top-of-the-line 580 4MATIC presents a new engine to the world for the first time, the 4.0-liter biturbo V8 with EQ Boost. EQ Boost is an integrated starter generator and a 48-volt onboard electrical system. The electric motor helps aid the combustion engine with acceleration, and the generator recuperates energy that can be supplied back into a battery. Furthermore, the EQ Boost eliminates the need for a belt drive, which saves space and makes the engine more compact. The electric system can also service features such as the air conditioning compressor and the water pump.