The C400  introduces the new C-class with the 329-hp twin-turbo V-6 that Mercedes will use in a host of other upcoming vehicles to give the power of a V-8 but with fewer jugs. Forget the 400 nomenclature; this engine is 2996 cc, and it feels every bit down the two cylinders until the boost comes on. Benz’s engineers have done all they can to shorten the wait, but it’s still possible to catch the engine napping in awkward situations, such as when diving into a lane of fast-flowing traffic.

Once the pressure is up, the C400’s distant rising rumble suggests precision parts in a kinetic frenzy. A slight wheeze betrays the presence of spinning turbines, but it’s far more charming than disruptive. And the wee six makes small numbers out of the 60-mph run: 4.7 seconds, which is strong. We liked other numbers, too, from the 13.3-second quarter-mile to the 160-foot fade-free stopping distance. This heavy C hustles.

The just-average 0.88-g skidpad is a byproduct of the 4MATIC’s ability to create understeer. This is not the kind of four-wheel-drive system meant to rally-kick the rear end sideways out of a corner. Rather, it’s an all-weather assistant that generates sales in snowy states without really adding anything to the car’s dry-road handling. As you turn into a corner, you feel the mass resisting a change of direction. The suspension needs a millisecond to roll over and compress, then the turn happens. It’s all fairly quick and, by model-year-2004 standards, a wonder of athletic ability, but it doesn’t raise the blood pressure. We did like the brake feel and always found the pedal response reassuring.

As with Benzes of yore, the C400 thrives best on the interstate with its firm ride, excellent seats, and solid sense of straight ahead. A lot of highway driving at a mere 10 mph over produced a 22-mpg test average, 1 mpg better than the car’s EPA-rated city number. To get the 29-mpg highway rating, we’re thinking you’ll need a steady tailwind.

Welcome practicalities of the C-class design include the split-folding rear seats and an 18-gallon fuel tank, though at 13 cubic feet, the trunk may struggle to hold all the suitcases of four passengers.

Reminders that you’re not actually in an S-class: the distinct thrum invading the otherwise quiet cabin as the tires roll over coarse pavement, and foot boxes that are small enough that your knees bump against the door and console. Here and there you find some hard plastic. In the back, passengers get good knee and head clearance but limited footroom, and the two rear-facing air vents in the center armrest proved inadequate on a hot day.

Shades of the S-class include an in­teri­or well decorated with silvery jewels and detailed down to the millimeter with fine lines of stitching; swaths of warm, textured black ash wood; and thin filaments of brightwork. A Burmester sound system comes standard in this model and is worth it just for the fabulous speaker shower heads. Option packages bring in most of the other notable finery, such as the $2300 interior package that includes leather upholstery, power for the front-passenger seat, illuminated doorsills, and splashes of mood lighting.

The  multimedia package installs a rearview camera, nav system, and big 8.4-inch high-res screen that dominates the center console. Here, as in the CLA, Mercedes eschews a hideaway screen or one elegantly faired into the dash for what is basically a television on a stick. With all of the C’s pleasing interior design surrounding it, the LCD display stands out like an electronic billboard plopped down in Beverly Hills.

To the COMAND system’s central superknob, Benz adds a sort of mouse/touchpad on top meant to ease your passage through the system’s menus and infotainment choices. It will take you some time with a patient salesperson plus a close reading of the 20-page section of the owner’s manual on this device before full familiarity sets in. In the meantime, you may wonder why the radio station changed when you reached for your latte, or why the nav is suddenly showing you Pismo Beach.

A  Driver Assistance package brings in a bunch of safety items, some detestable—such as lane-keeping assist, which buzzes the steering wheel when you approach lane lines. The AIRMATIC air suspension is $1190 and lets you set the car’s aggression level with an “Agility” switch. The choices are typical: eco, comfort, sport, and sport plus. Sport dials up the right suspension and shift-map settings for eager driving but locks out top gear unless you take manual control. So you must needlessly waste fuel if you just want the car to feel a little firmer.

Lavishly trimmed and optioned, this prince of all Cs looks racier in its AMG-inspired clothes than it feels, but we’re not dinging it for that. The person who buys this C400 isn’t looking for ultimate lateral grip or hand-slicing steering sharpness, but maxi-button luxury in a small package. And at this odd job, the car excels.