The 2010 M-Class includes the ML350, ML350 BlueTEC, ML450 Hybrid, ML550, and ML63 AMG.4MATIC all-wheel drive is available on the ML350 and ML450 Hybrid.

The M-Class isn't so large that it's cumbersome or hard to park, but it comfortably seats five and carries plenty of stuff.As daily transportation, it doesn't feel like a truck, and it won't beat its driver or passengers up.Yet it has the potential for some fairly serious off-highway adventuring.Properly equipped, an ML can tow up to 7,200 pounds.The M-Class is more than powerful enough in any of its variations.And it offers the safety equipment, luxury accoutrements, style and smooth finish expected of a Mercedes-Benz.

The ML450 Hybrid features a new two-mode gasoline/electric powertrain that brings EPA City/Highway ratings of 21/24 mpg, the former better than any M-Class and the latter a match for the ML350 BlueTEC diesel.Where the diesel wins is on purchase price and towing capacity.Either may qualify for a tax credit.Either reaches 60 mph in about the same eight seconds as an ML350.The ML450 is offered only as a three- or five-year lease.

The ML350 offers a choice of rear-wheel drive or 4MATIC all-wheel drive.The two-wheel-drive model is lighter, more fuel efficient, offers a lower price, the four-wheel-drive model is better for inclement weather acceleration or slippery launch ramps.Power mongers have a choice of two V8 engines, the ML550 that reaches the 0-60 benchmark in less than six seconds or the ML63 AMG's hand-made 6.2-liter that manages the sprint in less than five seconds.The AMG comes with more standard features than the ML550, and its base price is $34,000 higher.

Since it first appeared for 1998, the M-Class has helped make luxury SUVs a familiar part of the automotive landscape.The second and current generation, which arrived for 2006, is larger inside and out than the original, and also aerodynamically slipperier.M-Class offers five-passenger seating.The GL-Class offers seven-adult-seat accommodations.

The M-Class is built using car-like unibody construction with isolated front and rear subframes, a technique that emphasizes rigidity, decreased vibration and lowers weight.A double-wishbone front suspension and four-link independent rear suspension emphasize sedan-style dynamics.Yet with more than eight inches of ground clearance and electronic traction aids the M can venture further down the beaten path than most owners know or dare to. Mercedes owners will fell at home in an M-Class and appreciate the cache and engineering the Mercedes brand will find plenty to like here.Shoppers may also consider the Porsche Cayenne, BMW X5, Audi Q5 and Q7, Cadillac Escalade, Land Rover LR4, and Lexus GX460.

The ML350 and ML350 4MATIC are powered by a 3.5-liter V6, generating 268 horsepower and 258 lb-ft of torque.

The ML350 ($45,700) and ML350 4MATIC ($48,200) are powered by a 3.5-liter V6, generating 268 horsepower and 258 lb-ft of torque.They come with cloth upholstery, automatic climate control, automatic headlights, eight-way power seats, sunroof, rain-sensing wipers, Tele-Aid emergency communication, COMAND control interface, an eight-speaker stereo with a six-CD changer, and 19-inch wheels with 255/50R19 all-season tires.

The ML350 BlueTEC ($49,700) is equipped similarly but powered by a 210-hp 3.0-liter turbo-diesel V6 with a full 400 pound-feet of torque available from 1600 rpm.

The ML450 Hybrid ($549 for 60 months or $659 for 36 months) uses a modified Atkinson-cycle 3.5-liter V6, 275-hp gasoline engine and 288-volt nickel-metal battery pack powered electric motors for a combined system output of 335 hp and 381 lb-ft of torque.

The ML550 ($56,750) gets a 382-hp, 391 lb-ft 5.5-liter V8, more aggressive front end, moonroof.

Options include the Premium 1 package ($3,950) with a navigation system with voice-control, a rearview camera, HD Radio, Sirius Satellite Radio with Real-Time Traffic, iPod/MP3 media interface cable, power liftgate, auto-dimming inside mirror, power folding outside mirrors, memory for driver's seat and mirrors, power adjustable steering column, and a 115v power outlet.Premium 2 ($5,950) combines all of the above with harman/kardon Logic7 surround-sound with 12 speakers and Keyless Go.

The leather package ($1,750) includes burl walnut wood trim and ambient interior lighting.Heated seats and steering wheel, illuminated door sills, park sensors, trailer hitch, and a wood and leather are all available.A Lighting Package ($970) adds bi-Xenon headlamps that shine around curves, a headlamp washing system, and fog lamps.Rear-seat DVD entertainment ($1,880) is also available.Three-zone climate control ($780) and 20-inch AMG wheels ($770) are available for the ML550, and an Appearance package ($970) is offered for gasoline ML350s.

The ML63 AMG ($91,050) features a 6.2-liter V8 that generates 503 hp, along with an AMG SpeedShift transmission, AMG suspension, high-performance P295/40ZR20 tires on 20-inch wheels, larger brakes, AMG instruments, premium leather upholstery, and the contents of the Premium 1 and 2 Packages.Options are fewer, and include the trailer hitch, illuminated door sills, 21-inch wheels ($1580), rear-seat entertainment, and heated rear seats.

Safety features on all models includes two-stage front airbags for the driver and front passenger, side-impact airbags front and rear torso protection, and curtain-style head protection airbags.A rollover sensor can activate both the seat-belt tensioners and curtain airbags if the vehicle senses an imminent rollover, and Pre-Safe automatically tightens the front seat belts and moves the front passenger seat to a position that can provide better protection.Side windows close to provide better support for the curtain air bags.If the system senses an impending rollover, the sunroof also closes.An Electronic Stability Program comes standard along with advanced anti-lock brakes with electronic brake-force distribution.A tire pressure warning system is also standard.

The rear bumper incorporates recessed red reflectors below the taillight clusters, and a stainless-steel skid plate that wraps around dual exhausts and taillamps that gives the impression they are inset by cuts into the tailgate, the whole effect one of more movement.With dark glass and rear-most pillar, the substantial rear door pillar makes the roof look like it's cantilevered over the back of the car and merely floating in place.

In profile, all ML model wheel arches loom large and prominent.There's an unmistakable character line rising front to rear with a widening rub strip as it goes, and a forward-slanting C-pillar that frames trapezoidal rear side glass.

A high-tech scratch resistant paint, embedded with thousands of flecks of ceramic, is standard.It should be welcomed by those owners who actually decide to challenge overgrown trails, or those who share their garages with kids, toys and bicycles.The Premium 1 package includes an optional power liftgate operated with the key fob.Several cargo organizing devices are available as accessories.

The ML63 AMG is not as readily distinguished from the ML550 as in the past.The divider between the upper and lower cooling slots in its front bumper is black rather than body color, suggesting one huge opening (an aesthetic improvement); and its 20-inch wheels feature a five-spoke design with intriguing three-dimensional curves.Quad oval exhausts provide some distinction at the rear.

Most M-Class come standard with MB-Tex upholstery, a synthetic substance that looks and feels more leather-like than the real stuff on some less-expensive cars.Wood included with the leather package is the real thing, doors and dash are soft-touch, and while more of it is plastic than you realize, hard plastic is used only where it's a good idea near the floor, under seats, and so on.

The front seats themselves provide all-day comfort and lateral support without being restrictive to the point that close-quarter maneuvering, or simply sliding in and out, become annoying.The rear seats in the M-Class aren't as supportive as the front seats, but they are roomy, have low-profile headrests for good rear vision and fold down without leaving a shoulder belt dangling from the ceiling.

The distinctive four-spoke steering wheel echoes Mercedes sedans, as do the thumb buttons on it and stalks behind.The shifter on the right handles drive, reverse, neutral and park and frees space in the console, while manual gear selection of the seven speeds is done with shift buttons on the back side of the upper spokes.The busier left-side stalks include a busy one with signals, high-beams and front wipe wash, cruise control, and a third if you have the power-adjustable steering column.The main light switch is to driver's left and most ancillary controls are in the row under the climate control.

Four huge, round air vents spread across the dash panel, which is dominated by a deeply hooded instrument cluster with sharp graphics and prominent chrome trim around the tachometer and speedometer.A central information window between the gauges can be programmed to supply about as much driving and maintenance information as one driver can stand to absorb.

The steering wheel has a nice, thick rim that's easier to keep your thumbs out of when driving off pavement.We're fond of the optional steering wheel that's finished with the top half in wood and the bottom half in leather, but some drivers don't like wood (especially with rings) or mixed materials on their wheels and not all are available with heat.

Primary climate and audio controls are in the center stack above the console.The center stack is dominated by the elements of the COMAND system and a 6.5-inch color screen which incorporates entertainment, telephone, and navigation displays.In some respects it may appear daunting while in others, such as simply pressing the asterisk and the numbers to go direct to your favorite radio channel.

The COMAND system was revised for 2009, and now incorporates a standard in-dash, six-disc DVD / CD changer and a Bluetooth interface that allows a phone still in a pocket or purse to be operated through the car's audio system.The optional iPod/MP3 interface, Sirius Satellite Radio, and HD radio all integrate into the COMAND interface.COMAND can play tracks stored on a data CD, DVD or SD memory card.The system can also display maps and directions for the optional hard-drive navigation system, which can be set up for Sirius Real Time Traffic and Zagat restaurant ratings.

The ML63 AMG has heavily bolstered sport seats upholstered with Nappa leather and an Alcantara insert across the shoulder bolsters.Its entire dashboard is wrapped with leather.There's a bit more brightwork inside than in the other models.The ML63 also features a leather-wrapped sport steering wheel, unique AMG instrument graphics and stainless-steel pedals with rubber studs.

Cargo space is a respectable 29.4 cubic feet, expanded seat to 72.4 cubic feet by folding the rear seat.The rear seat folds fairly easily and is split 60/40.The load height in back is high, as it is with many SUVs, but M-Class offers nearly as much cargo-hauling room as full-size truck-based SUVs.

The BlueTEC diesel boasts more torque than the ML550's hefty V8: 400 pound-feet from 1600-2400 rpm vs.391 from 2800-4800.And it's torque, not horsepower that gets you going and pulls trailers up hills.(With both properly equipped, the BlueTEC tows the same 7,200 pounds as the ML550.)

The new ML450 Hybrid delivers the best mileage in M-Class, its principal advantage in the city where it betters a like-performing ML350 by 6/4 mpg.The ML350 BlueTEC diesel, which goes as quickly, tows substantially more and weighs less for better handling, delivers the same EPA estimated 24 mpg highway and 18 in the city.Note that in our experience with other Mercedes diesel cars and SUVs the EPA numbers have been pessimistic.

Fuel economy for the gasoline-V6 ML350 4MATIC rates 15/20 mpg City/Highway (16/21 2WD).The ML550 is rated 13/18 mpg.The ML63 AMG gets 11/15 mpg.

Mercedes estimates near-identical 0-60 mph times of 8.0, 7.9 and 7.8 seconds, respectively, for the ML350 BlueTEC diesel, ML350 gasoline V6 and ML450 Hybrid.Yet that doesn't tell the whole story, because where the gas engine might jump across the crosswalk quicker the diesel comes on with serious urge and rarely needs a downshift in traffic or on the highway when an ML350 does.Potentially noteworthy, turbocharging maintains power better in high-altitude environs though not like it did years ago.

The ML550 is more fun to drive.The 5.5-liter V8 engine will take this 2.5-ton SUV from 0-60 mph in 5.6 seconds, and then settles down to a background burble by the time you reach seventh-gear overdrive.The seven-speed automatic offers a manual-shift mode, and it's the best automatic Mercedes has built.It's flexible, in that it kicks down to a lower gear more quickly than its predecessors, and it almost always keeps the engine in the most productive part of its power band.Yet its overdrive top gear makes for quiet high-speed cruising and better fuel economy.

During several days of hard driving in mountainous, sinuous terrain, we found the ML550 a hoot.The suspension is good at minimizing body roll in high-speed corners, and it smoothes dips and potholes well.The standard 19-inch wheels and tires and the power rack-and-pinion steering deliver a nice feel of the road, and quick reactions when necessary.At high speeds through mountain passes, the ML550 leans over a little, takes a set, and then grabs the ground and turns the corners; the all-wheel drive system helps keep it going where you point it.

Critics have complained with some justification about the electronically actuated and modulated Sensotronic brake system that Mercedes-Benz has been feeding gradually into all of its models over the last few years.We're getting used to them, and they'll stop the M-Class right now without much pedal effort.They've also improved considerably since they were first introduced.Yet they don't have the smooth, linear feel of the best mechanically actuated brake systems.Nice smooth stops can be tricky without practice, although we can't say how feel is affected in the Hybrid which does battery regeneration while slowing.

On the trail or sand, the M-Class offers typical electronic advantages: a Downhill Speed Regulation software control that maintains the 4-12 mph downhill pace you set through the wheel controls, and a Start-Off Assist that keeps the vehicle from drifting backward in Drive or forward in Reverse on steep hills.Very handy for novices and easy to use; many more experienced four-wheelers will leave it off but they'd be buying a Land Rover or Jeep instead.

All no-hybrid M-Class models are rated at a significant 7,200-pound towing capacity with the optional Class III towing package, but note the tongue weight rating may be the limiting factor.We have little doubt that the diesel and 550 would be up for the job, as would the ML63 but its 20-inch tires aren't ideal for trailering, and would reserve the 350 gas and 450 for watercraft or dirt-bike trailers of less than 4000 pounds.

We've driven the ML63 AMG and it certainly has appeal: a people hauler to do battle with Porsche Cayennes and BMW X-M's in the stoplight derby or blast through big sweeping curves much faster than decorum or good sense might suggest.The ML63 is fast, dashing from 0 to 60 mph in less than five seconds, and, with the torque of a large V8 and the high-revving character of a sports car engine, it can be fun to drive.But it's also big and heavy, so don't think sports car.Through the twisties where we sampled it, changing directions quickly and often, the ML63 AMG is not exactly fun.Its massive tires mean plenty of grip.The steering is fairly quick for such a hefty machine, but also quite light, and the package conspires to feel twitchy, almost unsettling.

Correspondents G.R.Whale and Jim McCraw contritubed to this NewCarTestDrive.com report.