It's inevitable the car widely considered the benchmark for luxury performance would garner its share of scorn, worship and admiration. The BMW 3-Series has certainly garnered equal parts of each and every luxury brand has the 3er in its sights.
Most competitors' shots just glance off the 3-Series' tautly drawn sides, but the Cadillac ATS is one entry that's pierced almost all of the protective armor on BMW's iconic sport sedan. Yes, the 3-Series still has the whirling-propeller badge on the hood for prestige, but whether it stands as the best compact luxury sports sedan is in question.
First, a disclaimer: We've already put the 2017 Cadillac ATS through our updated scoring system and it earned a 7.0 out of 10 overall. We haven't crunched the numbers for the 3-Series in our new system, but we're eager to see the results. Stay tuned to this space as we update those numbers. (Read more about how we rate cars.)
First, the basics. The 3-Series sedan was new for the 2012 model year, and it's been mostly carried forward since then. They're handsome vehicles, though not so different from the last generation, all the traditional BMW design bits and pieces in full flourish. Sculpted on its sides, it's a bit sallow at the front and rear, and tall of glass. The cockpit's less impressive, somehow, with a faint Toyota flavor in the sweeping curve that separates the driver from the passenger. It's dark, filled with small buttons and iDrive in some cases, and gets an afterthought of a wide LCD screen stuck to its dash on nav-equipped models, in one of the least attractive integration attempts we've seen on any luxury brand in recent memory.
The ATS? It was new for 2013. Its style is watered-down Art & Science angles, but it's still convincing in its extroverted attitude, from its exaggerated headlamps to the V-crested rear lamps. The cabin's an understated win, with great organization and a high degree of finish that really centers on versions equipped with the iPad-like CUE system. Most ATS cabins are awash in the serene blue glow that CUE casts, while drivers run audio, navigation, climate, and phone with its touchscreen, steering-wheel, or voice controls.
That unified theory of functionality has its fans, and its detractors. BMW's tried its hand at it with iDrive, and though it has Pandora streaming and such, the roller-controller school of thought looks hopelessly out of date next to CUE's swiftly changing screens, haptic feedback, and proximity-sensing surfaces. Both have their bugs, and their quirks--but a CUE-equipped ATS can come in thousands less than some 3-Series sedans without a rearview camera. Both sedans offer packages of advanced safety gear like blind-spot monitors and lane-departure warning systems; but only the ATS has seat-mounted buzzers that vibrate you when you've crossed the double-yellow line.
In terms of interior space and usability, it's the BMW's turn to shine. It's bigger inside, about the same size outside. Its rear seat is habitable, its trunk more usable; the ATS suffers from a severe lack of rear-seat leg room and cargo space, by comparison.
It's a total dogfight on all these fronts, but on the battlefield where the BMW 3-Series and Cadillac ATS will be waging war from now on, is on the performance front. The base ATS is no longer a concession to price, its 272-hp turbo-4 sits atop the base 3-Series; the 335-hp ATS V-6 and 320-hp BMW 340i turbo-6 now seem like luxuries in the class.
With turbo-4 engines the easiest to compare, and multi-link independent suspensions teamed with electric power steering and optional adaptive ride controls, the mass-market editions duke it out, the ATS pulling up as evenly as any sedan ever has with the Bimmer. It's the 272-horsepower ATS turbo-4 that takes on BMW's 240-hp turbo-4, with nearly identical acceleration times, and a choice of manual and automatic transmissions, as well as rear- or all-wheel drive.
Of course, there's always the nuclear option: the BMW M3 (or M4, as a coupe), with 425 hp, or Cadillac's new ATS-V sedan or coupe, with 455 hp. We'll handle that shootout on a separate line item. Yeah, we'll take one for the team.
Between the less lofty versions, which holds the real performance edge? It's really too close to call; even in straight-ahead stability and cornering transitions, Cadillac's dialed in the cornering magic that used to be the province of BMW's MacPherson struts and links. Neither car requires the expensive upgrade suspensions, though Cadillac's magnetically-controlled shocks seem to have more sublime control than BMW's adjustable setup.
With even fuel economy nearly identical, the BMW 3-Series and Cadillac ATS sedan still offer a clear choice. The BMW fans we know wouldn't consider looking elsewhere. Now that Cadillac's in the business of selling phenomenally balanced handling in a compact package, with superior looks and a tech interface second to nothing in the class, it puts that long-standing loyalty to a severe stress test. The fact that ATS sedans are widely, and heavily, discounted, makes the choice all that more difficult.
The ATS isn't a knockout blow to the Bimmer, but it's thoroughly good where other four-doors like the Lexus IS, the Infiniti Q50, and Acura TLX come up ever so slightly short. It's the most nimble, tossable Cadillac ever. And it's a more electrifying entry, since it's new, and since in a system called CUE it offers one of the most tightly integrated telematics and infotainment systems short of a Tesla Model S.
The ATS may inch ahead in the ratings when we're all done adding up the 2017 numbers, but you'll need to peruse the our full reviews in order to figure out which one suits you best—and which is the new archenemy.