Driving the 2015 Mercedes-Benz C-Class, the newly eager middle child

When a new sibling is born, the formerly youngest child in the family will often demonstrate signs of what is known as regression, attempting to compensate for the loss of a privileged status by dropping down a few developmental milestones. He might give up on achievements like using the toilet, feeding himself, and sleeping through the night in the hopes of returning to being properly pampered.

What is less frequently discussed is the countervailing force of progression. The former lowest rung on the birth-order ladder will take the opportunity of the newborn’s appearance to define himself in opposition to this interloper. He’ll acquire new skills and capabilities that were within his grasp, but not seen as necessary or useful before. He’ll thus use the birth of the adorable and guileless new baby as a means to demonstrate the ways in which he is not a baby anymore: taking a jump and learning to read, or dress himself, or get a job.

Progression is clearly the case with the new Mercedes-Benz C-Class, which, with the recent introduction in the American market of a new entry-level model — the guileless and adorable CLA-Class — has truly matured.

Physically, the C-Class has hit a growth spurt, not only gaining nearly four inches in overall length — three of those between the wheels, (mostly in the back seat) — and more than an inch-and-a-half in width. It has also begun to resemble, in all the best ways, a downsized version of its refined eldest brother, the S-Class. A proportionally long hood, a proper and upright cabin, and a short rear deck featuring a prodigious rear overhang give the C-Class a handsome and elegant formality. And he’s lost his baby fat as well, dropping up to 220 lbs. through the intensive use of high strength steel and aluminum.

The little bugger’s bones and muscles have received a workout as well. When introduced here in the second half of this year, the car will come in two, all-wheel-drive (4MATIC) only guises. The C300, will feature the exact combination of 4-cylinders, turbocharging, and direct injection offered by key category competitors like the Audi A4, BMW 328i, and Cadillac ATS, with an estimated output of 241 hp and 273 lb-ft. The C400 will counter its colleagues as well with a new-to-the-U.S. twin-turbo V-6 that will put down 329 hp and 354 lb-ft of torque. Pricing hasn’t been announced, but figure on a significant differential from the $29,900 base price of the CLA and don’t be surprised if you can crest $50,000 for a fully optioned model.

A category-first air suspension floats all four wheels, and Mercedes’ suite of autonomous robotic driving systems, known as Intelligent Drive, can also be integrated, allowing the car to truly start, stop, and steer itself, features we took full advantage of during some hideous rush hour traffic. We’re still undecided if it’s frightening or amazing, but it does work, and well.

Each of the two cars can also be had in Sport or Luxury permutations, with materials, wheels and tires, and trim bits to match. (An additional Sport Package can be added to supplement the sportiness of the Sport model, if it’s not sporty enough for you.) Here’s the basic roadside cheat code: the Sport car has a giant three-pointed star integrated into the grille, like an old Gullwing; the Luxury car has a traditional big grille and Benz hood ornament, like a 1970s W123 sedan. We like them both.