Review: 2009 Mercedes ML320 Bluetec Diesel
12-01-08, 03:26 PM
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Review: 2009 Mercedes ML320 Bluetec Diesel
By CL member request, a review of the 2009 Mercedes ML320 Bluetec Diesel
http://www.mbusa.com/mercedes/MBHome...320BTC&yr=2009
In a Nutshell: Well-engineered with many safety features, but with some interior quirks and awkward-feeling brakes.
I got a request for a review of this vehicle from a fellow CL member, so I decided to review it now, before I do the big annual Holiday review coming up shortly (I'm waiting for that particular car to arrive). I was also somewhat interested to see how well a job Mercedes has done with its new Bluetec Diesel, which replaces the previous CDI diesel. I was very impressed with the job VW has done with the Jetta's new 2009 TDI diesel, so, naturally, I expected as much, if not more, out of the Bluetec diesel in a vehicle that costs more than twice as much as a TDI Jetta. (Like with the TDI/DSG powertrain in the Jetta, I was not disappointed with this one either, but more on that later).
Mercedes introduced the car-based, unibody M-Class SUV, in late 1997, as a new-for-the-American-market 1998 model. A special new plant was built at Tuscaloosa, AL, for its production, with labor hired from the local vicinity and elsewhere around the country (German labor, by this time, had become prohibitively expensive, and auto manufacturers were starting to move out of German plants). The ML was introduced to a fairly accomodating auto press and market, but shared some of the press attention at that time with similiar but smaller, cheaper and simpler car-based SUVs like the Toyota RAV-4, Honda CR-V, and Subaru outback. Even in its upmarket position, the ML started a premium, unibody, car-based SUV trend that eventually included numerous rivals from Lexus, BMW, Infiniti, Acura, Audi, and Volvo, and Cadillac.
Unfortunately, the M-Class suffered from numerous, well-documented reliability problems, particularly in electronics/hardware, that were not ironed out within the first few years of production as with some other vehicles. This was not necessarily a bad reflection on the new plant's employees, its managers, or even the design of the vehicle itself, as other American plants producing foreign-designed vehicles had managed to do a good job. Nevertheless, for whatever reasons, the M-class continued with worse-than-average reliability for years (though the 2008 model may have shown a slight improvement), and, because of that unreliability, never was on Consumer Report' Recommended list, despite its competent results in CR's general testing and its good safety features. Of course, the M-Class now has a new, superb, state-of-the-art, Bluetec diesel and other improvements for 2009....time will tell if the improvments this year eventually pay off in better reliability.
For 2009, three verions of the M-Class are sold in the American market; the ML350, ML320 BlueTec Diesel, and the ML550. The ML350 has a gas 3.5L V6, the ML550 a gas 5.5L V8, and the ML320, of course, the 3.0L V6 Bluetec diesel. I chose an Arctic White ML320, with black (MB-Tex) wood/"leather"(?) interior for the review/test-drive. Details coming up.
Model Reviewed: 2009 Mercedes ML320 BlueTec Diesel
Base Price: $48,600
Major Options:
P01 Hi-Tech/Power Package: $3850
Heated Front Seats: $720
Wiring for Rear Entertainment: $150
Destination/Freight: $875
List price as reviewed: $54,195
Drivetrain: 4Matic AWD with 50/50 torque split, 3.0L, longitudinally-mounted, Turbocharged, BlueTec V6 Diesel, 210 HP @ 3800 RPM, Torque, 398 Ft-lbs. @ 1600-2400 RPM, 7-speed automatic transmission with manual Sport-Shift and paddle shifters.
EPA Mileage Rating: 17 City, 24 Highway
Exterior Color: Arctic White
Interior: Black M-B Tex/Burl Walnut wood trim
PLUSSES:
Built in Alabama, with American labor, for the "Buy American" crowd.
Mercedes-solid roll cage/crash-safety features.
Superb diesel technology hard to tell from a gas engine.
Strong torque/acceleration at lower RPMs.
Fairly good agility and steering response for an SUV this size.
Fairly smooth-riding suspension and run-flat tires.
Wind and engine noise well-muted.
Seamless 4Matic AWD system.
Silky-smooth transmission shifts in both manual and automatic modes.
Nicely-done paint job.
Solid doors/exterior sheet metal.
Excellent, clear primary gauges.
Classy, well-done wood trim inside.
Solid, well-done interior hardware and controls.
Good front and rear seat legroom/headroom.
Very well-finished, roomy, efficient cargo area.
Chrome-metal cargo tie-down hooks instead of plastic.
Standard first-aid kit.
Superb stereo sound.
Easy-to-fold rear seats for cargo room.
7200-lb. towing capacity with Class-III hitch.
MINUSES:
Noted reliability problems on previous versions.
4/50 bumper-to-bumper/drivetrain warranty not very generous for an upmarket vehicle.
Low-sulfur Diesel fuel costs a dollar more than premium gas.
Diesel urea-injection system requires periodic fill-ups.
18-24 MPG OK but not particularly impressive for a mid-sized AWD diesel SUV.
Awkward-feeling, spongy brakes.
No low-range transfer case for off-roading.
Moderate body roll.
Numb steering feel.
Moderate road noise with the run-flat tires.
Relatively poor underhood layout.
Twin outside mirrors too narrow for optimum vision.
Super-dull paint colors make a funeral home look cheerful in comparison.
Manual tilt/telescoping steering column, even with optional packages.
Somewhat confusing turn signal and cruise-control column stalks.
Complex NAV/stereo controls and functions.
Awkward, stub-stalk transmission shifter.
Cheap plastic grille and front-end trim.
Ultra-cheap, rough-feeling sun visors.
M-B Tex vinyl/leather pattern for interior trim not particularly plush-feeling.
No oil dipstick.
Gas filler-cap only locks with the doors.
EXTERIOR:
The exterior of the new ML320, despite some recent styling tweaks, is not greatly different from that of its predecessors. As you first walk up to it, it is pretty much recognizable from earlier models. It is still rather efficiently (and box-like) designed for good interior room.....more on this below. The headlights, grille, and taillights are slightly more aero-swept than before, and the side-pillars have a slightly different shape. But, visually, an ML it was, and an ML it remains.
I generally had a high opinion of the exterior and its overall quality/features, however. The unibody frame, doors, hood, and and sheet metal, as expected of a Mercedes product, felt strong and solid (better, IMO, than that of the newer GL-Class). The paint job was quite well-done; smooth and even, with very little orange peel, though the paint color choice is so dull that it would make Murphy's funeral home look cheerful....some military-camoflauged vehicles actually stand out more. The twin side mirrors are quite tall, but a little too narrow for optimum side vision....a minor ***** in Mercedes generally outstanding safety features. They do, however, have decently-strong plastic housings, side-mounted turn signals, and power-swivel, flush with the body, for clearance. Most of the exterior trim was well-done, solid, and well-attached. The big multi-slat grille/front-end trim, however, with the Mercedes Tri-Star logo, was cheesy and made of very flimsy plastic, especially for a 50K-plus vehicle.
The gas filler-door, back on the right, has an unusual feature in that it only locks when the outside doors are locked; something to think about with today's expensive, low-sulfur diesel fuel, which, as I write this, was some $1.00 a gallon more than premium 93-octane gas. Ground clearance was fine for any reasonable amount of snow, mud, trails, and light-duty off-road work, but the ML, as evidenced by the lack of a low-range transfer case, is not designed for serious, hard-core off-road stuff......the stuff you would do with a Jeep Wrangler or Range Rover. If you want to play Paul Hogan/Crocodile Dundee the Mercedes way, you have to move up to the far more expensive (and unbelievably strong/tanklike)
Gelandewagen (G-Wagon), or, to a lesser extent, the GL-class. Still, even with its car-based unibody, the ML320's diesel gives it a pretty hefty 7200-lb. tow rating with a Class III hitch.......not bad for a vehicle of this type.
UNDERHOOD:
Lift the solid, well-made hood, and two nice gas struts hold it up for you (expected, of course, in this class of vehicle). The hood has a fairly thick insulation pad underneath that covers about half of it, due to a big, oval-square rubber-seal ring that completely surrounds the engine when the hood is shut and helps to keep out engine noise (and it does work.....more on that below). Mercedes includes this feature not only on the Bluetec 320 diesel but the gas-engine ML350/550 as well.
As with many luxury/upmarket vehicles therse days, I wasn't impressed with the general underhood layout. The 3.0L diesel V6 fits in, longitudionally-mounted, a little on the tight side, though there is room in front of the block to reach down to the intercooler components underneath. The engine, as usual with upmarket cars these days, has a big, full-size plastic cover that blocks just about everything except a couple of filler caps. Also, the engine, in a growing trend with Mercedes and BMW, lacks an oil dipstick. Oil level/oil use is monitored by electronic sensors instead...a risky setup, IMO, in a vehicle like this that has a noted history of electronic problems. Perhaps that is one reason why Mercedes, like other German automakers, only warrants their drivetrains for 4 years/50,000 miles, instead of the more common 5/60, 6/70, 7/100, or 10/100 used by American, Japanese, and Korean automakers. On the bright side, all of the underhood filler caps and reservoirs are easy to reach, although I forgot, this time, to check where the battery was..........maybe I need to start using a review checklist, like I did when I was a pilot doing an airplane pre-flight.
INTERIOR:
I was generally quite pleased wth the interior, although there were several annoying things inside......I'll get them out of the way first. The transmission shifter, a short stub-stalk on the right side of the steering column, had an awkward feel/pattern, and took some getting used to. The sun visors, despite their built-in vanity mirrors, were insultingly cheap for a 50K-plus vehicle, having basically the look and feel of dried stucco. The tilt/telescope steering column, despite my test car's optional power/tech package, had manual controls, and didn't adjust very smoothly. The stereo/NAV controls, except for ON/OFF/VOLUME, like in many upmarket cars so equipped, were complex and not easy to operate. Some functions can be voice-controlled, although the system's female voice had some difficulty recognizing/processing the commands of either my own rather nasal voice recovering from a cold or the Asian-accent English of the salesperson there. The black M-B "Tex" upholstery on the seats and steering wheel rim was, supposedly, a leather derivitive, but had the look and feel of textured vinyl...certainly not the silky-smooth leather seen on Mercedes AMG products. On the left side of the steering column, the larger, lower turn-signal stalk can be sometimes mistaken for the smaller, upper, cruise-control stalk....and vice versa. And, for small hands, the lower one is not an easy finger-reach from the wheel rim.
Those quirks aside, there is little else to complain about inside. The gauges are simple, crystal-clear, and easy to read. The woodtone trim is classy, well-fitted, and well-done, although not quite as exquisitely beautiful as on the Jaguar XF and Infiniti M35/45. The Harmon-Kardon stereo sound is everything a KISS/AC-DC/Heavy Metal (or even a classical-music orchestra) fan would want....it approaches the Lexus Mark Levinson stereo quality, and is one of the best I've seen in a German-designed vehicle. The stereo controls, despite their complexity, manage to avoid the annoying I-Drive controller found in some other Mercedes products. The dash has a nice, soft-touch but durable cover material. The seats, despite the cheap-feeling, vinyl-ized/leather surface, are comfortable. There is plenty of headroom/legroom, both front and back, for any reasonably-sized adult, a result of the rather conservative box-design of the body and high roof. The interior hardware, controls, and buttons/levers all had a solid, substantial feel to them. Unlike the flimsy stalks in many VW, Audi, and BMW products, the steering column stalks, though confusing, also had a strong, substantial feel to them, like the rest of of the interior hardware. The headrests are simple, slick, and easy to flick right up and down for the best position. The NAV video screen, though complex, had good, high-contrast figures, and doubled as a back-up screen when the car was placed in reverse. The glove box was solid and had an upper mini-compatment. And, for a German-designed vehicle, there were a fair number of cupholders/storage compartments/cubbyholes inside, something that German cars have tended to lack until recently.
CARGO AREA/TRUNK:
Raise the solid, well-made rear hatch/liftback, and you are treated to a tall, roomy, very nicely-finished cargo area....one of the car's best features. Plush, black carpeting covers the floor and both side walls. A first-aid kit, like with Lexus vehicles, is provided in a side compartment on the left. Real chrome/metal (not cheap plastic), flexible, tie-down cargo loops are provided on both left and right. The tall roofline and squared-off rear end adds to the cargo room, just it does to headroom. Both split-rear seats are easily flipped-down for added cargo room, without having to remove the headrests like in many other vehicles. Just flip one easy lever to tilt the bottom cushion forward, then another easy lever to lower the seatbacks down. Under the rear floor, there is no spare tire (real or temporary) or compressed-air bottle, as the ML320 comes with run-flat tires that dispense with the need for them. Those tires, without further damage, can be run with no air pressure at all for up to 50 miles at 50-55 MPH.....they rely on sidewall strength to support the weight of the car. Where the spare tire/jack assembly would usually go, under the floor, you find, instead, the filler-cap for the diesel's urea-injection tank (an emission-control device), which must be periodically refilled with a urea solution (roughly every 10,000 miles, as I understand it). Mercedes, as they told me today, does NOT offer this as free maintenance; you have to pay for it.
ON THE ROAD:
Start up the turbocharged, 3.0L Bluetec V6 diesel with a thick, plastic "key" inserted into a rectangular hole in the dash, and it is clear that the Mercedes engineers, like VW with the Jetta's TDI, have really done their homework with this new diesel. Like VW's TDI, the engine fires instantly, with no glow-plug waiting time, emits no visible black soot out the tailpipe, is odorless, and is almost dead-silent at idle inside the car, with only a very faint diesel tick-tick noise (and no diesel smell) with the windows down. Compare THAT with the junk diesels sold 25-30 years ago. America, you have to get those noisy, stinky, slug-like, hard-to-start diesels of the 70s and 80s out of your memory and go see and drive something like this. You will be amazed......just like with the VW TDI. On the road, you don't ever have to go over 3000-3500 RPM with this powerplant......the almost 400 ft-lbs of torque come on at only 1600 RPM, and, while not a drag-racing machine by any means (remember, this is an almost 5000 lb. SUV) you still get a healthy shove in the back (Mercedes quotes an official 8.0 second 0-60 time, which is excellent for a V6-equipped SUV this size). Most of the torque comes on at or below 3000 RPM, so you don't have to run the RPM's way up, and the transmission's 7 speeds, though you could consider them a little overkill, aid acceleration and flexibility even more. The Bluetec's engineering and previously-mentioned ring-seal underhood cut engine noise, even on the road, down to the point where you would never guess you are in a diesel....all you hear is some exhaust chuffle, and even that is not too loud. Mileage, though, at 18/24 EPA ratings, is (officially) not that much greater than with a gas engine this size, but with a ligh foot and constant, moderate speeds, the average driver could probably do 30 on the road, as the VW TDI, rated at 40 highway, often does 50 or more with a good driver. A factor, of course, to take into account, though, is the high cost of low-sulfur diesel fuel and its limited availability, even if you get good mileage with it.
The 7-speed transmission, as described earlier, has what I consider an awkward, stub-shifter stalk on the column, but, otherwise, is a delight to use. In full-automatic mode, shifts are butter-smooth and silky; they remain so, even in manual mode, with the diesel's hefty torque going into them. Using the steering-wheel-mounted paddles is more of a small click-click motion than a flap-wiggle, and holding the (+) paddle back reverts the transmission to full-automatic mode. A Downhill-Descent Control, for very steep grades, works through the transmission and anti-lock brakes to hold the car's speed to 4 MPH.....this may not function temporarily if the brakes build up too much heat, to allow them to cool.
Handling is a mixed bag, wih a reasonable (even decent) amount of agility and steering response combined with a rather dull, overboosted steering feel (this is no BMW) and a moderate amount of body roll, mostly from the high center of gravity. It's reasonably competent in the handling department for a mid-to-large size, 5000 lb. SUV, but I wouldn't push it in turns like a sports car, especially if you take advantage of the 7200 lb. towing capacity. Ride comfort is smooth for an SUV, with reasonably good bump absorbtion, and I did not notice any of the fore/aft porposing motions that SUVs often have on bumps....this is remarkable with the run-flat tires, considering their ultra-stiff sidewalls and tendency to ride stiffly. Wind noise is faily well-muted; there was some road noise from the run-flat tires, even on smooth surfaces.
As with other Mercedes products, I was not impressed with the brakes. There were no pedal-spacing problems with my big foot, but the brakes had a noticeable sponginess, a lack of firmness in the pedal, and, like other M-B products, the sensation of slightly dragging for a second or two after you lift your foot off the pedal. They are a noticeable improvement, though, over the awful electro-hydraulic brakes M-B used to put in some of its cars....those brakes were all-electronic activated, with the hydraulic master cylinder only there as an emergency back-up. Those brakes generated so many customer complaints that M-B not only discontinued them but retro-fitted customers' cars with conventional hydraulic units at factory expense.
THE VERDICT:
The ML320 Bluetec is, overall, an impressive machine. It has a superlative state-of-the-art diesel powerplant, impressive low-RPM torque, a silky-smooth transmission, a comfy, space-efficient, nicely-trimmed interior, all-weather versatility, mild off-road capability (but lacking a transfer case for the rough stuff), hefty towing capacity, a superb Harmon-Kardon stereo, a super-plush, easy-to-use, rear cargo area, a slick paint job, traditional Mercedes-quality safety features (Mercedes and Volvo generally lead the industry in this area), and a reasonably good ride/handling combination, despite some body roll.
But it also has some quirks and annoyances. Mercedes needs to redesign the brakes in many of its products (including this one) to get the vague, spongy, and dragging feel out of them. The power steering could use less boost and some more BMW-like feel to it. The transmission's stub-shifter, IMO, needs to be tossed out and a more conventional one used either on the column or the console.....Mercedes says this is to free up up space on the console, but I'm not convinced; even though the small stub-shifter feels solid, it appears to me to just be cost-cutting with a smaller, cheaper part. The leather upholstery needs to be smooth, real, LEATHER (like in the Mercedes AMG cars), not a grainy, imitation vinyl/leather product (Mercedes, of course, is not alone in cheapening the leather used in its products lately). It needs a longer driverain warranty to match that of its American and Asian competition. It needs an oil dipstick, IMO, under the hood...asking electronics to monitor the oil is like playing a game of Russian Roulette. And, last, its reliability, a known weak point in the past, may or may not still be a factor....only time, of course, will tell on that.
http://www.mbusa.com/mercedes/MBHome...320BTC&yr=2009
In a Nutshell: Well-engineered with many safety features, but with some interior quirks and awkward-feeling brakes.
I got a request for a review of this vehicle from a fellow CL member, so I decided to review it now, before I do the big annual Holiday review coming up shortly (I'm waiting for that particular car to arrive). I was also somewhat interested to see how well a job Mercedes has done with its new Bluetec Diesel, which replaces the previous CDI diesel. I was very impressed with the job VW has done with the Jetta's new 2009 TDI diesel, so, naturally, I expected as much, if not more, out of the Bluetec diesel in a vehicle that costs more than twice as much as a TDI Jetta. (Like with the TDI/DSG powertrain in the Jetta, I was not disappointed with this one either, but more on that later).
Mercedes introduced the car-based, unibody M-Class SUV, in late 1997, as a new-for-the-American-market 1998 model. A special new plant was built at Tuscaloosa, AL, for its production, with labor hired from the local vicinity and elsewhere around the country (German labor, by this time, had become prohibitively expensive, and auto manufacturers were starting to move out of German plants). The ML was introduced to a fairly accomodating auto press and market, but shared some of the press attention at that time with similiar but smaller, cheaper and simpler car-based SUVs like the Toyota RAV-4, Honda CR-V, and Subaru outback. Even in its upmarket position, the ML started a premium, unibody, car-based SUV trend that eventually included numerous rivals from Lexus, BMW, Infiniti, Acura, Audi, and Volvo, and Cadillac.
Unfortunately, the M-Class suffered from numerous, well-documented reliability problems, particularly in electronics/hardware, that were not ironed out within the first few years of production as with some other vehicles. This was not necessarily a bad reflection on the new plant's employees, its managers, or even the design of the vehicle itself, as other American plants producing foreign-designed vehicles had managed to do a good job. Nevertheless, for whatever reasons, the M-class continued with worse-than-average reliability for years (though the 2008 model may have shown a slight improvement), and, because of that unreliability, never was on Consumer Report' Recommended list, despite its competent results in CR's general testing and its good safety features. Of course, the M-Class now has a new, superb, state-of-the-art, Bluetec diesel and other improvements for 2009....time will tell if the improvments this year eventually pay off in better reliability.
For 2009, three verions of the M-Class are sold in the American market; the ML350, ML320 BlueTec Diesel, and the ML550. The ML350 has a gas 3.5L V6, the ML550 a gas 5.5L V8, and the ML320, of course, the 3.0L V6 Bluetec diesel. I chose an Arctic White ML320, with black (MB-Tex) wood/"leather"(?) interior for the review/test-drive. Details coming up.
Model Reviewed: 2009 Mercedes ML320 BlueTec Diesel
Base Price: $48,600
Major Options:
P01 Hi-Tech/Power Package: $3850
Heated Front Seats: $720
Wiring for Rear Entertainment: $150
Destination/Freight: $875
List price as reviewed: $54,195
Drivetrain: 4Matic AWD with 50/50 torque split, 3.0L, longitudinally-mounted, Turbocharged, BlueTec V6 Diesel, 210 HP @ 3800 RPM, Torque, 398 Ft-lbs. @ 1600-2400 RPM, 7-speed automatic transmission with manual Sport-Shift and paddle shifters.
EPA Mileage Rating: 17 City, 24 Highway
Exterior Color: Arctic White
Interior: Black M-B Tex/Burl Walnut wood trim
PLUSSES:
Built in Alabama, with American labor, for the "Buy American" crowd.
Mercedes-solid roll cage/crash-safety features.
Superb diesel technology hard to tell from a gas engine.
Strong torque/acceleration at lower RPMs.
Fairly good agility and steering response for an SUV this size.
Fairly smooth-riding suspension and run-flat tires.
Wind and engine noise well-muted.
Seamless 4Matic AWD system.
Silky-smooth transmission shifts in both manual and automatic modes.
Nicely-done paint job.
Solid doors/exterior sheet metal.
Excellent, clear primary gauges.
Classy, well-done wood trim inside.
Solid, well-done interior hardware and controls.
Good front and rear seat legroom/headroom.
Very well-finished, roomy, efficient cargo area.
Chrome-metal cargo tie-down hooks instead of plastic.
Standard first-aid kit.
Superb stereo sound.
Easy-to-fold rear seats for cargo room.
7200-lb. towing capacity with Class-III hitch.
MINUSES:
Noted reliability problems on previous versions.
4/50 bumper-to-bumper/drivetrain warranty not very generous for an upmarket vehicle.
Low-sulfur Diesel fuel costs a dollar more than premium gas.
Diesel urea-injection system requires periodic fill-ups.
18-24 MPG OK but not particularly impressive for a mid-sized AWD diesel SUV.
Awkward-feeling, spongy brakes.
No low-range transfer case for off-roading.
Moderate body roll.
Numb steering feel.
Moderate road noise with the run-flat tires.
Relatively poor underhood layout.
Twin outside mirrors too narrow for optimum vision.
Super-dull paint colors make a funeral home look cheerful in comparison.
Manual tilt/telescoping steering column, even with optional packages.
Somewhat confusing turn signal and cruise-control column stalks.
Complex NAV/stereo controls and functions.
Awkward, stub-stalk transmission shifter.
Cheap plastic grille and front-end trim.
Ultra-cheap, rough-feeling sun visors.
M-B Tex vinyl/leather pattern for interior trim not particularly plush-feeling.
No oil dipstick.
Gas filler-cap only locks with the doors.
EXTERIOR:
The exterior of the new ML320, despite some recent styling tweaks, is not greatly different from that of its predecessors. As you first walk up to it, it is pretty much recognizable from earlier models. It is still rather efficiently (and box-like) designed for good interior room.....more on this below. The headlights, grille, and taillights are slightly more aero-swept than before, and the side-pillars have a slightly different shape. But, visually, an ML it was, and an ML it remains.
I generally had a high opinion of the exterior and its overall quality/features, however. The unibody frame, doors, hood, and and sheet metal, as expected of a Mercedes product, felt strong and solid (better, IMO, than that of the newer GL-Class). The paint job was quite well-done; smooth and even, with very little orange peel, though the paint color choice is so dull that it would make Murphy's funeral home look cheerful....some military-camoflauged vehicles actually stand out more. The twin side mirrors are quite tall, but a little too narrow for optimum side vision....a minor ***** in Mercedes generally outstanding safety features. They do, however, have decently-strong plastic housings, side-mounted turn signals, and power-swivel, flush with the body, for clearance. Most of the exterior trim was well-done, solid, and well-attached. The big multi-slat grille/front-end trim, however, with the Mercedes Tri-Star logo, was cheesy and made of very flimsy plastic, especially for a 50K-plus vehicle.
The gas filler-door, back on the right, has an unusual feature in that it only locks when the outside doors are locked; something to think about with today's expensive, low-sulfur diesel fuel, which, as I write this, was some $1.00 a gallon more than premium 93-octane gas. Ground clearance was fine for any reasonable amount of snow, mud, trails, and light-duty off-road work, but the ML, as evidenced by the lack of a low-range transfer case, is not designed for serious, hard-core off-road stuff......the stuff you would do with a Jeep Wrangler or Range Rover. If you want to play Paul Hogan/Crocodile Dundee the Mercedes way, you have to move up to the far more expensive (and unbelievably strong/tanklike)
Gelandewagen (G-Wagon), or, to a lesser extent, the GL-class. Still, even with its car-based unibody, the ML320's diesel gives it a pretty hefty 7200-lb. tow rating with a Class III hitch.......not bad for a vehicle of this type.
UNDERHOOD:
Lift the solid, well-made hood, and two nice gas struts hold it up for you (expected, of course, in this class of vehicle). The hood has a fairly thick insulation pad underneath that covers about half of it, due to a big, oval-square rubber-seal ring that completely surrounds the engine when the hood is shut and helps to keep out engine noise (and it does work.....more on that below). Mercedes includes this feature not only on the Bluetec 320 diesel but the gas-engine ML350/550 as well.
As with many luxury/upmarket vehicles therse days, I wasn't impressed with the general underhood layout. The 3.0L diesel V6 fits in, longitudionally-mounted, a little on the tight side, though there is room in front of the block to reach down to the intercooler components underneath. The engine, as usual with upmarket cars these days, has a big, full-size plastic cover that blocks just about everything except a couple of filler caps. Also, the engine, in a growing trend with Mercedes and BMW, lacks an oil dipstick. Oil level/oil use is monitored by electronic sensors instead...a risky setup, IMO, in a vehicle like this that has a noted history of electronic problems. Perhaps that is one reason why Mercedes, like other German automakers, only warrants their drivetrains for 4 years/50,000 miles, instead of the more common 5/60, 6/70, 7/100, or 10/100 used by American, Japanese, and Korean automakers. On the bright side, all of the underhood filler caps and reservoirs are easy to reach, although I forgot, this time, to check where the battery was..........maybe I need to start using a review checklist, like I did when I was a pilot doing an airplane pre-flight.
INTERIOR:
I was generally quite pleased wth the interior, although there were several annoying things inside......I'll get them out of the way first. The transmission shifter, a short stub-stalk on the right side of the steering column, had an awkward feel/pattern, and took some getting used to. The sun visors, despite their built-in vanity mirrors, were insultingly cheap for a 50K-plus vehicle, having basically the look and feel of dried stucco. The tilt/telescope steering column, despite my test car's optional power/tech package, had manual controls, and didn't adjust very smoothly. The stereo/NAV controls, except for ON/OFF/VOLUME, like in many upmarket cars so equipped, were complex and not easy to operate. Some functions can be voice-controlled, although the system's female voice had some difficulty recognizing/processing the commands of either my own rather nasal voice recovering from a cold or the Asian-accent English of the salesperson there. The black M-B "Tex" upholstery on the seats and steering wheel rim was, supposedly, a leather derivitive, but had the look and feel of textured vinyl...certainly not the silky-smooth leather seen on Mercedes AMG products. On the left side of the steering column, the larger, lower turn-signal stalk can be sometimes mistaken for the smaller, upper, cruise-control stalk....and vice versa. And, for small hands, the lower one is not an easy finger-reach from the wheel rim.
Those quirks aside, there is little else to complain about inside. The gauges are simple, crystal-clear, and easy to read. The woodtone trim is classy, well-fitted, and well-done, although not quite as exquisitely beautiful as on the Jaguar XF and Infiniti M35/45. The Harmon-Kardon stereo sound is everything a KISS/AC-DC/Heavy Metal (or even a classical-music orchestra) fan would want....it approaches the Lexus Mark Levinson stereo quality, and is one of the best I've seen in a German-designed vehicle. The stereo controls, despite their complexity, manage to avoid the annoying I-Drive controller found in some other Mercedes products. The dash has a nice, soft-touch but durable cover material. The seats, despite the cheap-feeling, vinyl-ized/leather surface, are comfortable. There is plenty of headroom/legroom, both front and back, for any reasonably-sized adult, a result of the rather conservative box-design of the body and high roof. The interior hardware, controls, and buttons/levers all had a solid, substantial feel to them. Unlike the flimsy stalks in many VW, Audi, and BMW products, the steering column stalks, though confusing, also had a strong, substantial feel to them, like the rest of of the interior hardware. The headrests are simple, slick, and easy to flick right up and down for the best position. The NAV video screen, though complex, had good, high-contrast figures, and doubled as a back-up screen when the car was placed in reverse. The glove box was solid and had an upper mini-compatment. And, for a German-designed vehicle, there were a fair number of cupholders/storage compartments/cubbyholes inside, something that German cars have tended to lack until recently.
CARGO AREA/TRUNK:
Raise the solid, well-made rear hatch/liftback, and you are treated to a tall, roomy, very nicely-finished cargo area....one of the car's best features. Plush, black carpeting covers the floor and both side walls. A first-aid kit, like with Lexus vehicles, is provided in a side compartment on the left. Real chrome/metal (not cheap plastic), flexible, tie-down cargo loops are provided on both left and right. The tall roofline and squared-off rear end adds to the cargo room, just it does to headroom. Both split-rear seats are easily flipped-down for added cargo room, without having to remove the headrests like in many other vehicles. Just flip one easy lever to tilt the bottom cushion forward, then another easy lever to lower the seatbacks down. Under the rear floor, there is no spare tire (real or temporary) or compressed-air bottle, as the ML320 comes with run-flat tires that dispense with the need for them. Those tires, without further damage, can be run with no air pressure at all for up to 50 miles at 50-55 MPH.....they rely on sidewall strength to support the weight of the car. Where the spare tire/jack assembly would usually go, under the floor, you find, instead, the filler-cap for the diesel's urea-injection tank (an emission-control device), which must be periodically refilled with a urea solution (roughly every 10,000 miles, as I understand it). Mercedes, as they told me today, does NOT offer this as free maintenance; you have to pay for it.
ON THE ROAD:
Start up the turbocharged, 3.0L Bluetec V6 diesel with a thick, plastic "key" inserted into a rectangular hole in the dash, and it is clear that the Mercedes engineers, like VW with the Jetta's TDI, have really done their homework with this new diesel. Like VW's TDI, the engine fires instantly, with no glow-plug waiting time, emits no visible black soot out the tailpipe, is odorless, and is almost dead-silent at idle inside the car, with only a very faint diesel tick-tick noise (and no diesel smell) with the windows down. Compare THAT with the junk diesels sold 25-30 years ago. America, you have to get those noisy, stinky, slug-like, hard-to-start diesels of the 70s and 80s out of your memory and go see and drive something like this. You will be amazed......just like with the VW TDI. On the road, you don't ever have to go over 3000-3500 RPM with this powerplant......the almost 400 ft-lbs of torque come on at only 1600 RPM, and, while not a drag-racing machine by any means (remember, this is an almost 5000 lb. SUV) you still get a healthy shove in the back (Mercedes quotes an official 8.0 second 0-60 time, which is excellent for a V6-equipped SUV this size). Most of the torque comes on at or below 3000 RPM, so you don't have to run the RPM's way up, and the transmission's 7 speeds, though you could consider them a little overkill, aid acceleration and flexibility even more. The Bluetec's engineering and previously-mentioned ring-seal underhood cut engine noise, even on the road, down to the point where you would never guess you are in a diesel....all you hear is some exhaust chuffle, and even that is not too loud. Mileage, though, at 18/24 EPA ratings, is (officially) not that much greater than with a gas engine this size, but with a ligh foot and constant, moderate speeds, the average driver could probably do 30 on the road, as the VW TDI, rated at 40 highway, often does 50 or more with a good driver. A factor, of course, to take into account, though, is the high cost of low-sulfur diesel fuel and its limited availability, even if you get good mileage with it.
The 7-speed transmission, as described earlier, has what I consider an awkward, stub-shifter stalk on the column, but, otherwise, is a delight to use. In full-automatic mode, shifts are butter-smooth and silky; they remain so, even in manual mode, with the diesel's hefty torque going into them. Using the steering-wheel-mounted paddles is more of a small click-click motion than a flap-wiggle, and holding the (+) paddle back reverts the transmission to full-automatic mode. A Downhill-Descent Control, for very steep grades, works through the transmission and anti-lock brakes to hold the car's speed to 4 MPH.....this may not function temporarily if the brakes build up too much heat, to allow them to cool.
Handling is a mixed bag, wih a reasonable (even decent) amount of agility and steering response combined with a rather dull, overboosted steering feel (this is no BMW) and a moderate amount of body roll, mostly from the high center of gravity. It's reasonably competent in the handling department for a mid-to-large size, 5000 lb. SUV, but I wouldn't push it in turns like a sports car, especially if you take advantage of the 7200 lb. towing capacity. Ride comfort is smooth for an SUV, with reasonably good bump absorbtion, and I did not notice any of the fore/aft porposing motions that SUVs often have on bumps....this is remarkable with the run-flat tires, considering their ultra-stiff sidewalls and tendency to ride stiffly. Wind noise is faily well-muted; there was some road noise from the run-flat tires, even on smooth surfaces.
As with other Mercedes products, I was not impressed with the brakes. There were no pedal-spacing problems with my big foot, but the brakes had a noticeable sponginess, a lack of firmness in the pedal, and, like other M-B products, the sensation of slightly dragging for a second or two after you lift your foot off the pedal. They are a noticeable improvement, though, over the awful electro-hydraulic brakes M-B used to put in some of its cars....those brakes were all-electronic activated, with the hydraulic master cylinder only there as an emergency back-up. Those brakes generated so many customer complaints that M-B not only discontinued them but retro-fitted customers' cars with conventional hydraulic units at factory expense.
THE VERDICT:
The ML320 Bluetec is, overall, an impressive machine. It has a superlative state-of-the-art diesel powerplant, impressive low-RPM torque, a silky-smooth transmission, a comfy, space-efficient, nicely-trimmed interior, all-weather versatility, mild off-road capability (but lacking a transfer case for the rough stuff), hefty towing capacity, a superb Harmon-Kardon stereo, a super-plush, easy-to-use, rear cargo area, a slick paint job, traditional Mercedes-quality safety features (Mercedes and Volvo generally lead the industry in this area), and a reasonably good ride/handling combination, despite some body roll.
But it also has some quirks and annoyances. Mercedes needs to redesign the brakes in many of its products (including this one) to get the vague, spongy, and dragging feel out of them. The power steering could use less boost and some more BMW-like feel to it. The transmission's stub-shifter, IMO, needs to be tossed out and a more conventional one used either on the column or the console.....Mercedes says this is to free up up space on the console, but I'm not convinced; even though the small stub-shifter feels solid, it appears to me to just be cost-cutting with a smaller, cheaper part. The leather upholstery needs to be smooth, real, LEATHER (like in the Mercedes AMG cars), not a grainy, imitation vinyl/leather product (Mercedes, of course, is not alone in cheapening the leather used in its products lately). It needs a longer driverain warranty to match that of its American and Asian competition. It needs an oil dipstick, IMO, under the hood...asking electronics to monitor the oil is like playing a game of Russian Roulette. And, last, its reliability, a known weak point in the past, may or may not still be a factor....only time, of course, will tell on that.
Last edited by mmarshall; 12-01-08 at 08:52 PM.
) and confirms a lot of what I'd been researching on the ML Bluetec... thanks for the review!!
12-01-08, 04:06 PM
#3
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Having recently driven the VW TDI, I was also interested to see how the Mercedes Bluetec compared, though, of course, it is a larger diesel meant for larger, heavier vehicles than the four-cylinder VW diesel. And, unlike the TDI, it requires urea-injection for emissions.
12-01-08, 04:15 PM
#4
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Great work Mike! I actually saw one of these on the road recently. Personally I really like the ML exterior styling a lot. The interior leaves me very very cold (went to a ML driving event a few years ago). I can agree on the brake comments.
Fantastic towing capacity it has. The 54k asking price, IMO is steep.
Fantastic towing capacity it has. The 54k asking price, IMO is steep.
12-01-08, 04:31 PM
#5
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Thread Starter
Thanks.
You mean a new Bluetec, right? The ML, in general, is a very common vehicle.....there's nothing unusual about it.
I think you will find the new ML interior a little nicer. The 2008 and 2009 models have warmer and less stark/Teutonic-like interiors than the rather plain-looking ones of years ago. And they use some classy wood trim now, too.
The exterior, to its credit, hasn't changed much.....it was always sharp-looking.
Nothing unsafe, of course, about M-B brakes (M-B and Volvo don't lead the automotive-safety category for nothing), but, to me the brakes are unpleasant to use........I just don't like their feel and sensations.
Not much steeper, really, than a lot of its competition........Q7, X5, GX470, FX35/45, SLX, Touareg, etc.........
I actually saw one of these on the road recently.
Personally I really like the ML exterior styling a lot. The interior leaves me very very cold (went to a ML driving event a few years ago).
The exterior, to its credit, hasn't changed much.....it was always sharp-looking.
I can agree on the brake comments.
Fantastic towing capacity it has. The 54k asking price, IMO is steep.
Last edited by mmarshall; 12-01-08 at 04:37 PM.
12-01-08, 06:01 PM
#6
The gas door locking is similar to almost any BMW on the market right now as well. I don't think security is an issue unless you leave your car unlocked when you leave it, but then there's more things than fuel security to be wary of.
I agree that MB's brakes are spongier in feel than the sharp response usually found on say, a BMW.
The shifter design was first implemented on the 2002 BMW 7 Series I believe. I think the upcoming 7 series may have reverted back to a console mounted unit, but still electronic nonetheless.
What's next? Venza????
I agree that MB's brakes are spongier in feel than the sharp response usually found on say, a BMW.
The shifter design was first implemented on the 2002 BMW 7 Series I believe. I think the upcoming 7 series may have reverted back to a console mounted unit, but still electronic nonetheless.
What's next? Venza????
12-01-08, 06:43 PM
#7
Lexus Fanatic
Thread Starter
Normally, as most of us, especially single people, don't readjust the wheel that often, I don't consider a power tilt/telescope or memory feature that big a deal, even on a luxury vehicle like this, but this particular manual system wasn't the smoothest-operating one around, especially the pull-out telescope function. It felt like the column and its housing could use some more machining or a little grease.
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12-01-08, 07:08 PM
#8
Lexus Fanatic
Thread Starter
Some vehicles go one step further and have a lockable inside-release lever for the flap door. It is secured, with its own specific lock, by the regular door/ignition key, and will not work with a valet key. The VW Jetta TDI I drive a couple of weeks ago had that feature....a separate inside lock for the flap door.
I agree that MB's brakes are spongier in feel than the sharp response usually found on say, a BMW.
The shifter design was first implemented on the 2002 BMW 7 Series I believe. I think the upcoming 7 series may have reverted back to a console mounted unit, but still electronic nonetheless.
What's next? Venza????
Next year, I plan the Chevy Camaro and, by CL request, the next-generation BMW 7-series (when available).
And, sometime this month, the annual special Holiday review I do every year. I won't tell you what car that one will be, but I guarantee you won't be disappointed.
Last edited by mmarshall; 12-02-08 at 03:54 PM.
12-01-08, 07:16 PM
#10
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A useful vehicle? Yes, but for towing. I don't see any other benefit of this vehicle over the RX400h, other than perhaps offroad capability. It seems to me it would be more worth it to buy the cheaper, greener, more economical, and quicker RX400h. And with the RX450h expected to be even better, well MB had better hope that their planned ML hybrid can hit that mark as well.
12-01-08, 07:28 PM
#11
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12-01-08, 07:37 PM
#12
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Thread Starter
A useful vehicle? Yes, but for towing. I don't see any other benefit of this vehicle over the RX400h, other than perhaps offroad capability. It seems to me it would be more worth it to buy the cheaper, greener, more economical, and quicker RX400h. And with the RX450h expected to be even better, well MB had better hope that their planned ML hybrid can hit that mark as well.
M-B parts/service, of course, can be quite expensive as well, but you are dealing with a much less-complex vehicle in the ML320.
In CAR CHAT, we have talked about this issue and debated it many times...........the difference in complexity between diesels and hybrids, and which one makes more sense for what.
12-01-08, 09:08 PM
#13
The RX400H, though is a far more complex vehcle, with a regular gas engine up front and, as I understand it, THREE electric motors.....one with the gas engine up front and one on each rear wheel, which gives it electric-motor AWD. Granted, the Lexus 6/70 drivetrain warranty is longer and better than the 4/50 Mercedes warranty (I made an issue of that in the review), but once the warranty is out, any repairs (or accident damage) needed on the RX400H could be quite complex and expensive.
M-B parts/service, of course, can be quite expensive as well, but you are dealing with a much less-complex vehicle in the ML320.
In CAR CHAT, we have talked about this issue and debated it many times...........the difference in complexity between diesels and hybrids, and which one makes more sense for what.
M-B parts/service, of course, can be quite expensive as well, but you are dealing with a much less-complex vehicle in the ML320.
In CAR CHAT, we have talked about this issue and debated it many times...........the difference in complexity between diesels and hybrids, and which one makes more sense for what.
You do realize that current Hybrids are more reliable than Diesels?
Electric motors require no maintainance and should work for the lifetime of the car... I have yet to hear of single failure, and we have over 1 million Toyota hybrids on the roads.
And yes, even Edmunds rated RX400h (which is very old by now) better than ML320. It is pretty much better in everything.
What will happen with new RX450h with 10% more power and 8% better mpg? :-)
12-02-08, 04:17 AM
#14
Lexus Fanatic
Thread Starter
ehm, lol.
You do realize that current Hybrids are more reliable than Diesels?
Electric motors require no maintainance and should work for the lifetime of the car... I have yet to hear of single failure, and we have over 1 million Toyota hybrids on the roads.
And yes, even Edmunds rated RX400h (which is very old by now) better than ML320. It is pretty much better in everything.
What will happen with new RX450h with 10% more power and 8% better mpg? :-)
You do realize that current Hybrids are more reliable than Diesels?
Electric motors require no maintainance and should work for the lifetime of the car... I have yet to hear of single failure, and we have over 1 million Toyota hybrids on the roads.
And yes, even Edmunds rated RX400h (which is very old by now) better than ML320. It is pretty much better in everything.
What will happen with new RX450h with 10% more power and 8% better mpg? :-)
A well-made diesel engine, with proper care, will last a minimum of several hundred thousand miles. As far as the below-average reliability history of the ML series itself is concerned, that is no secret, and I have already addressed that in the review....we don't need to rehash that here. It is also no secret that Toyota/Lexus/Honda-designed hybrids, as you note, have generally been reliable.
My comments, in response to an earlier posts, dealt simply with the differences in complexity between the two vehicles and the potential cost /difficulty of repair if something DOES go wrong, especially after the waranty has expired. An accident, requiring extensive repairs, can also happen at any time, to any vehicle, regardless of a car's reliability. If a vehicle is damaged in an accident, you or your insurance company, if it is not totalled, will have to deal with it, and reliability records, then, won't mean a thing.
Last edited by mmarshall; 12-02-08 at 04:24 AM.
12-02-08, 05:42 AM
#15
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