How can something this big and heavy drive so smoothly? That鈥檚 what I鈥檓 wondering after spending a short weekend roadtrip in a 2013 Mercedes-Benz GL350 Bluetec. Bumps and other road imperfections I know exist barely affect the GL350 in Comfort mode. As we escaped Los Angeles and made our way toward a nearby coastal city about 50 miles away, I began to appreciate how quiet the big SUV is, too. You do hear the GL鈥檚 diesel six-cylinder engine, but it鈥檚 not overly intrusive. I spent a few weeks driving Motor Trend鈥榮 long-gone Infiniti QX56 that had a 400-hp V-8, and of course, with that vehicle in mind, the GL350 left me wanting more power. Realistically, though, how quick should gigantic premium SUVs really be? For those who aren鈥檛 interested in the GL350鈥瞫 driving range and efficiency, the 2013 Motor Trend Sport/Utility of the Year is also offered in gas-engined GL450, GL550, and even GL63 AMG variants. On the road, my front passenger and I enjoyed the massaging seats, though I began to wish the central dash navigation screen was much bigger and the speedometer could switch places with the tachometer. When the GL goes in for a refresh, I hope Mercedes can find the space to include one of the S-Class鈥?12.3-inch screens. I used the adaptive cruise control almost the entire way down to our beach-side destination. Like other such systems, Mercedes鈥?technology allows you to adjust the following distance, and although the vehicle was a little aggressive braking and accelerating in slower traffic, it really helps make roadtrips more relaxing.

How can something this big and heavy drive so smoothly? That鈥檚 what I鈥檓 wondering after spending a short weekend roadtrip in a 2013 Mercedes-Benz GL350 Bluetec. Bumps and other road imperfections I know exist barely affect the GL350 in Comfort mode. As we escaped Los Angeles and made our way toward a nearby coastal city about 50 miles away, I began to appreciate how quiet the big SUV is, too. You do hear the GL鈥檚 diesel six-cylinder engine, but it鈥檚 not overly intrusive. I spent a few weeks driving Motor Trend鈥榮 long-gone Infiniti QX56 that had a 400-hp V-8, and of course, with that vehicle in mind, the GL350 left me wanting more power. Realistically, though, how quick should gigantic premium SUVs really be? For those who aren鈥檛 interested in the GL350鈥瞫 driving range and efficiency, the 2013 Motor Trend Sport/Utility of the Year is also offered in gas-engined GL450, GL550, and even GL63 AMG variants. On the road, my front passenger and I enjoyed the massaging seats, though I began to wish the central dash navigation screen was much bigger and the speedometer could switch places with the tachometer. When the GL goes in for a refresh, I hope Mercedes can find the space to include one of the S-Class鈥?12.3-inch screens. I used the adaptive cruise control almost the entire way down to our beach-side destination. Like other such systems, Mercedes鈥?technology allows you to adjust the following distance, and although the vehicle was a little aggressive braking and accelerating in slower traffic, it really helps make roadtrips more relaxing.

On the test track, the electronics fought us on the way to a 57.8-mph slalom speed and a 0.74g performance on the skid pad, the 20-inch Pirelli tires never getting the chance to squeal. Our test-driver didn't hold back on the slalom performance. In the same vein, the brake-throttle override is overdone, so left-foot brakers will have to adjust their driving to suit this vehicle. Most GL owners won't even notice, but the level of intervention here is far too high and too frequent to ignore. Like "Sport," "Utility" is a loaded word in today's automotive landscape. The 2013 Mercedes-Benz GL450 is not a parts hauler or a farm hand; the carpeting in the rear of this SUV is nicer than the stuff in most homes. It is, however, huge and the automatic fold-flat seats couldn't be easier to use. With all of the seats folded, the GL is the protector of 93.8 cubic feet of flat storage space complete with tie-downs, which should be more than enough for that new whatever from Restoration Hardware.

Fold just the third row and you're down to 49.4 cubic feet. With the third row in full effect, there are 16 cubic feet of space to play with. Unlike with most SUVs these days, this last figure isn't just some number thrown in to fill out a spec chart. The 2013 GL is a true seven-seater with a functional, usable third row that even adults can tolerate for extended periods of time. 400 Power Easy-Entry option automatically slides the first and second rows to allow non-gymnasts to ride in the way back. Rounding out the "U" part of the acronym, our GL450 was equipped with the On-/Off-Road Package that lumps together a two-speed transfer case and a six-mode driving program selector similar to the terrain selector found in Land Rovers. 1,050 adaptive damping system and lets you increase ground clearance by a full 4 inches. Thankfully it also adds a front skid plate. In practice, it works better than necessary given the way the GL will likely be used by its owners. The electronics that so hampered us on the road turn mild/medium off-roading into a drive in the park.

Just point it roughly in the correct direction and the adjustable suspension, sophisticated electronics and low-range capability will get you safely to that lakeside cabin you've got with running water, WiFi and satellite TV. 63,505 price tag, the GL350 is the base model of the GL line. The GL350 comes with all of the same goodies as the 450, but swaps out the 4.7-liter gasoline engine for a 240-hp 3.0-liter turbodiesel V6 twisting out a totally adequate 455 lb-ft of torque. In practice, the diesel is only marginally more efficient than the 450, returning 16.9 mpg in notoriously fuel-sucking L.A. Unsurprisingly, the diesel gets fully trounced by the 450 in all measurable performance tests. Zero to 60 mph takes 8.4 seconds (8.0 with rollout), with the quarter passing in 16.2 seconds at 84.8 mph. Braking is similar at 118 feet and handling suffers the same fate as the 450, with a 57.9-mph performance in the slalom and a 0.74g lap around the skid pad.

If those kinds of numbers matter to you, there's always the GL550. 87,805 base) and its 429-hp, 4.7-liter V8 is even thirstier. The 2013 GL450 is the middle child and arguably the most well-rounded of the three. Factor in base price and the constantly fluctuating cost of diesel and the 450 is the one to have. Thinking of the 2013 Mercedes-Benz GL450 as an SUV will quickly make budget-minded buyers spin with rage and curse the 1 percent. Instead, try to think of the GL as a hatchback, seven-seat luxury car that just happens to have all-wheel drive and enough ground clearance to clear a parking curb. Sure, the new GL isn't as long as an S-Class, but the build quality and the comfort are there. The road manners and isolation are there, too, with the big SUV swaddling the driver and all rows of passengers in cocoons of soft leather and perfectly machined trim. We haven't seen this kind of luxury in mass transit since the Pullman sleeper car. The trouble, then, comes down to perception. Pull up to the valet or the golf course in an S-Class and you've arrived. In the GL, you're merely showing up.