2017 Volvo S90 T6 vs. 2017 Cadillac CT6 2.0T vs. 2017 Mercedes-Benz E300: Size Matters
Small Engines, Big Technology: Three Takes on the Big Luxury Sedan
Large luxury cars used to be powered by throaty, grumbling eight-cylinder engines. Cadillac had its old Northstar V-8s, Mercedes-Benz a 4.3-liter, and Volvo a 4.4-liter V-8 in the mid-priced offerings. But downsizing is all the rage these days, and all three of those manufacturers' new mid-priced offerings are powered by diminutive 2.0-liter four-cylinder engines. Our testing suggests that you might not miss those extra cylinders.
The segment stalwarts are the ones leading the downsizing charge. The 2017 Mercedes-Benz E300 Sport is the German automaker's bread-and-butter mid-priced midsize sedan. Starting at around $50K and selling well-equipped for nearly 70 large, the E-Class targets the heart of the luxury sedan market with semi-autonomous driving technology, baby S-Class luxury, and a four-cylinder engine cranking out a respectable 241 hp.
Cadillac has historically been synonymous with big engines. It sold high-tech V-16 engines through the middle of the Great Depression and has been known for its high-power V-8s since the '60s. Yet its stunning don't-call-it-a-flagship 2017 Cadillac CT6 2.0T Luxury offers an engine with a quarter of the cylinders of its V-16 cars, a tried-and-true 2.0-liter turbocharged I-4 making a stout 265 hp.
You can always count on the Swedes to be just a little bit different. Although the 2017 Volvo S90 T6 AWD Inscription makes just as much of a visual impression as the Caddy and Merc, it differs ever so slightly under the hood. Yes, it too has a 2.0-liter four-banger, but the S90's is twin-charged, featuring both a supercharger and a turbocharger. The end result is a potent little engine making 316 hp. That's V-8 territory.
So are these small-engined thoroughbreds engaging to drive? Can they deliver flagship luxury?
Each sedan in this test brings a serious amount of technology to the segment. The Cadillac, Mercedes-Benz, and Volvo each offer their manufacturer's latest in semi-autonomous driving technology, because there's no greater luxury than doing as little work as possible.
Although each of these three vehicles takes a fundamentally different approach to luxury, all come nearly loaded and comparably equipped for our $70,000 cutoff price. Yeah, they're different sizes, but consumers don't buy size. They buy price. The winner of this high-priced four-cylinder shootout must be great to drive, luxurious, and offer impressive autonomous-driving credentials.
Big on Engineering, Short on Execution
Put the Cadillac through one corner, and it becomes immediately clear where Cadillac invested its money on the new CT6 sedan: chassis engineering. The CT6's bones are phenomenal. Extensive use of aluminum gets this big car's curb weight down to just 3,893 pounds, only 2 pounds heavier than the next-size-down E300, the lightest car here.
Ostensibly intended to bridge the gap between midsize and flagship luxury cars such as the E-Class and S-Class, the CT6 was designed to offer up the luxury and space of an executive bruiser like the big Merc while offering the driving experience of a midsize offering.
To the latter end, it excels; the CT6 may not have been designed to be a sports car, but it gives a fair approximation at the test track. Its 2.0-liter turbo-four packing 265 hp and 295 lb-ft of torque seems on paper to be overmatched for the Cadillac's long, low, and wide proportions, but it's our favorite engine available in the CT6. Paired with an eight-speed automatic, the Cadillac is the second-quickest of the trio to hit 60 mph, doing so in 6.4 seconds. Its drag strip performance is equally impressive, with the Caddy rolling through the quarter mile in 14.7 seconds at 92.8 mph.
Not impressive, compared to its Nordic and Germanic competition, is the CT6's 60-0 braking performance of 117 feet. Our tester's standard all-season tires may be to blame for this and for the CT6's third-place figure-eight performance, which surprised us given how composed the Cadillac felt from behind the wheel. The CT6 lapped the figure eight in 26.7 seconds at 0.66 g.
The Cadillac's on-road manners are hit and miss. On the interstate, the CT6 is an exceptional cruiser. "There's a bit of 'good old days Cadillac' in the way it goes down the highway," associate editor Scott Evans said. The car is quiet and comfortable with an especially well-mannered ride—considering the CT6 2.0T isn't available with Cadillac's Magnetic Ride Control suspension system. The turbo engine is pretty solid, too; it's responsive and quite capable of keeping the big Cadillac going at autobahn-esque speeds. "Smooth and torquey," senior features editor Jonny Lieberman said. "It's amazing to me that 2.0-liter engines have come so far. A generation ago this is what V-8s felt like." The eight-speed transmission is mostly up to snuff, too, although it did regularly exhibit rough 1-2 shifts, especially at parking-lot speeds.
Where the Cadillac could use some improvement is in the little details such as steering feel, as its steering is lacking the feedback we've come to expect from Cadillac. The bigger problem is the "safety" cinching seat belt, which attempts to slice the driver in two like a cheese wire every time you turn a corner with any modicum of pace. "The constant hugs from the seat belt drive me insane," technical director Frank Markus said. "I'm almost tempted to remove my seat belt." Don't do this.
Cadillac's radar cruise control and lane keep assist systems are stopgap measures until the brand's delayed semi-autonomous Super Cruise system arrives. Unfortunately, Cadillac has decided that CT6 2.0T buyers don't need radar cruise control, with the system only available on V-6-equipped cars. The radar cruise control system on a CT6 3.0TT we tested worked as-advertised, but the stopgap's stopgap on the CT6 2.0T—a simple forward collision alert radar—is inadequate in a car of this class. The CT6's cruise control can actually use the front-facing collision radar to sense the distance the Cadillac is from the car in front of it, The CT6's lane keep assist function is also lacking; it's fine when the road is well-marked and its curves exceedingly gentle, but once it does cross a line, the system ping-pongs the car back and forth between lane markers.
Unfortunately for the Cadillac, things don't get better inside. The cavernous cabin gives a good first impression but falls apart on closer examination. First, the good: The cabin is nicely designed, if a bit understated. The front seats are well-bolstered, and the executive-spec back seat package is spacious and comfortable so long as you're not sitting in the middle seat. The seats themselves are also wrapped in thick baseball-glove-looking leather. Sadly, it all falls apart from there. The material choices in the CT6 are downright perplexing with a weird mix of leather, carbon fiber, chrome, and plastics. Most frustrating are the deep-grain plastics above the beltline and hard-grain plastics that lurk below it. The switchgear quality is maddening, too, ranging from a bespoke steering wheel to parts-bin buttons on the doors and center console.
And then there's CUE, Cadillac's infotainment system, which has somehow, impossibly, been made worse with the addition of a track pad. Although the finger-trace pad provides haptic feedback to the user, it's constantly overshooting the user's intended command. You're much better off ignoring it and just using CUE's touchscreenâprovided it's working, of course, as it froze multiple times before eventually crapping out, taking USB connectivity and charging with it.
Also inexcusable was the difference in quality between the rear-camera mirror and the backup camera. The rear-camera mirror, which displays an image from a second rear-facing camera, looked like a 4K video on a flat screen—although the focal length of the lens was disorienting for some. Worse still, the standard backup camera image was ridiculously grainy and crude. Seeing the two images displayed simultaneously is confounding. "This car is way too expensive for this nonsense," Evans said.
