Sumptuous interior, unflappable high-speed composure, respectable handling, room for six full-size adults, Bluetec diesel provides adequate performance and good fuel economy.
Eye-watering price, sluggish off-the-line acceleration, fussy center stack controls, second row's middle seat impinges on third-row knee room when in use, conventional rear doors are inferior to the sliding variety on such a large vehicle.
You know all those millionaire parents who are stuck ferrying their kids around in lowly minivans? Yeah, neither do we; we'd imagine the hired help usually takes care of that sort of thing. But this was evidently the target demographic for the Mercedes-Benz R-Class when it debuted a few years back. Here was a sleek six- or seven-seat people hauler with a luxurious interior and cool conventional rear doors instead of dorky sliding ones — perfect for well-heeled moms and dads who wanted to avoid the dreaded minivan stigma. Except the R-Class was practically dead on arrival in the U.S., recording consistently lethargic sales numbers as would-be buyers chose top-of-the-line minivan models or premium SUVs instead.
Enter the 2009 Mercedes-Benz R320 Bluetec, a better-late-than-never attempt to inject some life into the R-Class lineup. The big news is the R320's clean-burning Bluetec 3.0-liter turbodiesel V6 (shared with the GL320 and ML320), which meets the EPA's stringent 2010 emissions requirements for 50-state certification. Diesels have long been a fixture in European-market vehicles, but they're more tightly regulated in the U.S. Thanks to Bluetec, R-Class buyers can enjoy all the benefits of diesel power, including superior fuel economy and a reputation for durability, with the full blessing of Uncle Sam.
However, it's unlikely that this new power plant will single-handedly reverse the R-Class' fortunes. While the R320's combined EPA rating of 20 mpg is significantly better than the gas-powered R350 4Matic's 16 mpg, diesel costs 40 cents more per gallon than gas as of this writing. If diesel and gas are priced at $3.80 and $3.40, respectively, and the EPA's combined ratings are on the mark, then the R320 will cost barely 2 cents less per mile at the pump than the R350 4Matic, saving you a measly $2,000 over 100,000 miles. Moreover, if you can afford to drop $60 large on a new car, you're probably not too concerned about paying for gas in the first place.
To its credit, the Bluetec engine performs well enough, and the R320 is generally a pleasant vehicle, whether you're driving or riding. But we're afraid those well-heeled parents have already voted with their wallets — the R-Class simply isn't what wealthy shoppers want for their family transportation needs.
The all-wheel-drive 2009 Mercedes-Benz R320 Bluetec is motivated by a 3.0-liter turbodiesel V6 that was engineered expressly to achieve 50-state emissions certification. To make a complicated story simple, Mercedes' solution was to add a tank of urea and water mixture to the exhaust system. When the engine is running, this mixture is automatically injected into the exhaust stream, catalyzing a chain reaction that results in the conversion of polluting nitrogen oxides into harmless water vapor and nitrogen.
The Bluetec V6 cranks out 210 horsepower and 398 pound-feet of torque, the latter of which is available from 1,600-2,400 rpm. A seven-speed automatic with manual-shift capability — the only available transmission — routes this power to all four wheels via Mercedes' 4Matic system, which lacks low-range gearing in this application. At our test track, the portly 5,537-pound R320 galloped from zero to 60 mph in an unremarkable 8.8 seconds. Stopping distances were superlative for such a gargantuan vehicle, with a best stop of just 122 feet from 60 mph.
The diesel power plant is unfortunately a mixed bag. You can't ignore 398 lb-ft of torque, of course — the R320 really lunges forward once the Bluetec is on boil. However, it takes far too long for the transmission to act when you floor the gas from a stop. There's an exasperating delay (one-one thousand...) while the seven-speed slushbox unhurriedly mulls over your command, rather than the instantaneous turbodiesel torque we'd expect.
When the going got twisty, the R320 reminded us that it's no sport wagon, yet it surprised us with its refined road manners. A slalom speed of 58.1 mph might not be very impressive — indeed, it's more than 4 mph slower than the ML320 — but the big Benz handles high-speed sweepers with unexpected athleticism. The R320's steering is another point in its favor, as it's significantly more responsive and precise than the ML's gooey rack. The Airmatic electronically adjustable suspension seemed gimmicky, however, as switching from "Comfort" to "Sport" merely increased impact harshness without noticeably reducing body roll.
EPA fuel economy estimates for the 2009 Mercedes-Benz R320 stand at 18 mpg city/24 highway and 20 combined. We recorded 20.8 mpg over about 1,100 miles of mixed driving.
The R320 rides firmly, even a bit harshly on occasion. More diesel clatter makes its way into the cabin than we'd like during part-throttle acceleration, and road noise was a mild annoyance over certain surfaces. As a highway cruiser, however, this outsized wagon is wunderbar. The power-adjustable, leather-trimmed front seats are superbly supportive, and the R320's prodigious length and steeply raked windshield made us feel as though we were piloting our own personal high-speed train. Speaking of high speeds, that's where the R320 thrives — American speed limits are quite simply an insult to its autobahn breeding.
Passengers in our test car's spacious second row were treated to their own climate controls and a glass roof, as well as coddling seats that wouldn't have looked out of place in a private jet. Even the optional middle seat is hospitable for an adult, though it impinges on third-row knee room when locked in place. If the middle seat isn't occupied, it can spring forward to a less obtrusive location, enabling two adults to fit in the third row with ease. However, there's no substitute for sliding doors in terms of convenience, especially in tight parking lots, no matter how wide the R320's stretched conventional rear doors may open.
Visibility in the 2009 Mercedes-Benz R320 is excellent, with glass galore and a commanding driving position. The center stack controls are annoyingly labor-intensive, however, as the R320's COMAND interface lacks the control knob we've come to expect in premium vehicles, forcing you to use four directional arrow keys and an "OK" button instead. Compounding the problem is the smorgasbord of identical-looking black buttons surrounding the COMAND screen.
On the bright side, there's a nifty two-mode switch mounted on the inside lip of the power tailgate — the first function closes the tailgate, while the second closes it and then locks the entire vehicle. The sound quality of the optional Harman Kardon Logic7 stereo is good, if not great, and we appreciated this system's up-to-date technology, from its nicely integrated iPod interface to its hard-drive-based music storage.
In our real-world usability tests, a child safety seat fits easily in the R320's capacious second row, and our standard suitcase was a cinch to stow behind the third row. However, if you want to put a golf bag back there, you'll have to fold down at least one of those third-row seats manually, which requires a rather undignified amount of elbow grease.
Design/Fit and Finish
The R-Class' unusual exterior styling is perhaps one of its chief drawbacks beyond its price. The interior, on the other hand, is absolutely top-notch, with expensive-looking and -feeling materials just about everywhere. Even the glovebox door is covered in soft-touch material, for goodness' sake. Fit and finish was generally good on our test car, though we did notice a persistent rattle in the steering column.
Who should consider this vehicle
Those who don't mind paying through the nose in order to transport up to seven passengers in extraordinary comfort — and like the idea of using less of a finite resource than the gas-powered version.