2013 Cadillac XTS

As confusing as most alphanumeric car names have gotten in recent years, at least one constant has been that the letter "X" is generally indicative of a crossover. Then why did General Motorsuse this letter on its new 2013 Cadillac XTS luxury sedan? Well, for that, we'll have to look to the world of mathematics where "X" stands for an unknown variable or a placeholder. Now we're talking. The XTS is just an interim product sitting at the top of Cadillac's four-door food chain until the brand gets a true flagship in place. That sounds like a lot of resources to spend on what will likely be a one-and-done model, but the automaker needed to get something – anything – to replace the DTS.

So here you have the 2013 XTS. A big luxury sedan that was created to bridge the gap between Cadillac's recent past and its pending future. Going into our week with this XTS knowing that it was a stopgap measure proved to be both a blessing and a curse. On one hand, we know (or hope) that this car will act as a baseline for future high-end Cadillac models, but at the same time, we couldn't help but be mindful of past stopgap models, albeit in more entry-level segments, like the Cimarron and Catera.

The XTS proves that GM has finally gotten platform sharing to the point where it's no longer a trivial game of "spot the differences" between products from its various brands. Although the XTS shares many of its underpinnings with the Buick LaCrosse and the 2014 Chevrolet Impala, the three cars look nothing alike. Overall, the XTS – along with the ATS – shows a promising evolution of Cadillac's signature styling cues, and it looks remarkably good even on a car measuring almost 17 feet in length. From most angles, it's hard to criticize the design of the XTS, but the rear three-quarter view exposes some of the car's chunkiness, which is likely a result of the long rear overhang and the short decklid. The bulky rear end does help the XTS provide a cavernous 18 cubic feet of cargo space, which happens to be almost two cubic feet (an extra piece of luggage) more than theMercedes-Benz S-Class.

As nice as the overall styling of the XTS is, the exterior lighting might be the car's most expressive design elements. Up front, the headlights have a softer, rounder shape than previous Cadillac "Art & Science" designs, and there are also stylish lower running lights that line up perfectly with the headlights as if each side has a single light tube tucked in behind the fascia. Likewise, the vertical taillights also add to the car's appearance and even have some slight fin action that pays homage to classic Cadillacs. Perhaps the coolest exterior features on the XTS, though, are the illuminated door handles.

Most versions of the XTS get features such as adaptive headlights and the parallelogram-shaped exhaust outlets integrated into the rear fascia, but our tester was the top-of-the-line XTS-4 Platinum, which included a distinctive satin-chrome grille, standard 20-inch wheels and available White Diamond Tricoat paint.

Things get even better for the XTS once you look inside the car. GM has hit some pretty big milestones for interior quality over the last several years, including the 2008 Malibu and the 2010 LaCrosse, but it wouldn't be hard to argue that the XTS has one of the best-looking, highest-quality interiors GM has ever put together, and maybe even one of the best interiors found in a car priced under $100,000. Our Platinum tester had a nice mix of hues and materials, from three colors of leather used on the seats and instrument panel to the real wood, piano black and metallic accents. You can't touch anything inside this car without it being covered in some rich material, right down to the microfiber suede covering the headliner and A-pillars.

Front passengers are treated to wide, plush seats wrapped in soft perforated leather with heat and ventilating functions; you're not going to confuse the XTS seats for sport buckets, but as the theme of the car proved, it's not trying to be a sport sedan. Rear seat occupants are rewarded with plenty of headroom and legroom, as well as heated bottoms for the outboard passengers and sunshades for the side and rear window. For long hauls, the back seat is definitely the place to be.

Like the exterior, lighting also plays a big role inside the XTS with ambient lamps that emanate from just about everywhere at night, along with steering wheel, center stack and even rear-seat controls that illuminate only when the car is on.

In addition to the comfort afforded to XTS occupants, the car also delivers the expected amount of technology in this price class. Stealing a page from the Jaguar playbook, the XTS has a massive LCD screen for the gauge cluster that offers four different layouts with numerous information screens, and for more data, our tester also had a head-up display. Another innovative technology introduced on the XTS is the Safety Alert Seat, or as we like to call it, the butt buzzer. This uses separate buzzers on each side of the seat to relay different information to the driver. While driving, if the car starts to veer out of its lane to the left, then the left side of the seat bottom will vibrate; likewise, if the driver is backing up blindly and a car is approaching from the left, then the left side will vibrate.

In many regards, you just can't beat the XTS' interior, but there might be some objections to its functionality, mostly where it concerns the new CUE – Cadillac User Experience – interface and its associated technologies and controls. More than just an infotainment system, CUE is how passengers interact with the car, and like any other advanced infotainment technology (think MyFord Touch), there is definitely a learning curve to dealing with this system.

Most vehicle operations can be controlled either by touch or voice, but the capacitive touch buttons and touch-screen display are sometimes slow to respond, so after you've accidentally double-clicked an option, you have to find the way to back up a step. Further creating some potential confusion, there are no hard buttons on the center stack, so the capacitive controls there have a weird "thud" feedback when operated. Keeping in mind that this is the first generation of CUE, we actually applaud Cadillac for not pigeonholing the XTS' interior by leaving out high-tech features to appease former DTS clientele. It's not easy judging a system like this after having only used it for a week, but like with MyFord Touch, we bet that owners who deal with CUE on a daily basis will have far fewer problems with the interface than we did. And when frustration levels become too high, CUE's voice recognition system is actually one of the better we've used and can easily handle inputs for functions used often while driving like changing channels or finding albums to play on your smartphone.

While the styling, luxury and technology of the XTS are all top-notch, it's what you can't see that prevents this car from holding a flagship status. Many luxury sedans in this size and price range get rear-wheel drive and at least offer a V8 engine, but the XTS is only offered with a direct-injected 3.6-liter V6 engine powering the front wheels through a six-speed automatic transmission. Our test car was the 4,215-pound, all-wheel-drive model, making the engine's 304 horsepower and 264 pound-feet of torque feel underpowered at times. But this car isn't about speed or quickness. It's about a smooth, comfortable ride, and Cadillac nailed this aspect seeing as how the XTS will, like the DTS and STS it replaces, continue to be a popular choice among the snowbird crowd. (To properly experience this, we did our week-long test of the XTS in – you guessed it – Florida.)

Read more by Jeffrey N. Ross at Autoblog.com