2013 is a renaissance year for Cadillac’s product portfolio, as the brand adds two all-new “bookends”—the C-segment ATS sports sedan (full development feature coming in the Oct. 2 AEI) and the D-segment XTS sedan in both standard and long-wheelbase limousine versions.
The XTS takes over the role of the “big Cadillac,” replacing the aged DTS. Offered in front- and optional all-wheel drive, the roomy five-passenger sedan is strategically important for three reasons. First, it debuts Cadillac’s new design language that softens the previous sharp (and somewhat polarizing) exterior surfaces while bringing a crisp and classy overall form. Second, XTS is the brand’s technology flagship and the lead application for the new Cadillac User Experience (CUE) system, as well as General Motors’ new Safety Alert Seat with haptic feedback.
CUE features the industry’s first production use of a capacitive touch screen in a vehicle infotainment and human/machine interface system (http://www.sae.org/mags/aei/10449). GM aims to spread the CUE technology across its brands. The new safety seat that uses the driver’s choice of directional-signal vibrations or audible beeps, to alert the driver to potential traffic hazards, was codeveloped with Lear Corp. (http://www.sae.org/mags/aei/10882)
And third, but perhaps most important, XTS is the first new Cadillac to utilize a truly global architecture—GM’s stout Global Epsilon platform engineered for mid- and large-size cars.
“It’s been a while in coming, but XTS is the payoff to GM for fully implementing its global-architecture strategy,” observed veteran industry analyst Mike Jackson, Senior Manager of North American Vehicle Forecasts at IHS Automotive. “GM’s done global platforms before, of course, but without sufficient product differentiation. Now they’re executing that differentiation, and it’s allowing them to charge a substantial premium on greater scale.
“XTS should mint GM some substantial profits,” Jackson asserted. “It’s been a long time since a new Cadillac arrived with such a strong value proposition.”
According to Mark Moussa, GM’s Global Chief Engineer for Mid- and Full-Sized Cars, XTS represents the fullest extent of Epsilon’s dimensional “stretch.” First used on the 2008 Opel Insignia, the Epsilon architecture currently underpins Buick Regal and LaCrosse as well as the Chevrolet Malibu and 2014 Impala, among other nameplates. Its bandwidth is shown in the table.
The platform’s design allows XTS to be built on the same Oshawa, Ontario, line as its Regal cousin, along with the unrelated Chevrolet Camaro. And with 40 in (1016 mm) of rear-seat leg room—approximately 4 in (102 mm) more than the BMW 5 Series and Mercedes-Benz E-Class and 2 in (51 mm) longer than the Audi A6—it’s a key product for GM China, where it will enter production later this year. The trunk holds a commodious (though not industry leading) 18 ft³ (510 L) of luggage volume.
Haldex AWD optional
The XTS concept car unveiled at the 2010 Detroit auto show featured a plug-in hybrid electric vehicle (PHEV) powertrain, combining GM’s direct-injected 3.6-L V6 with a next-generation Two Mode hybrid transmission. “The PHEV in the concept got a lot of attention, but it was not in our initial planning portfolio,” said Jeanne Merchant, the XTS’s Vehicle Line Executive (the engineer who manages the program from concept to production).
The 3.6-L V6 (LFX code) is the XTS’s sole engine, producing an SAE-certified 304 hp (224 kW) and 264 lb·ft (355 N·m). It is mated with a Hydra-Matic 6T70 six-speed automatic with tap-shift control. The optional Haldex all-wheel-drive system with electronic limited-slip differential is similar to the system used on the Cadillac SRX. It is capable of splitting up to 1300 N·m (959 lb·ft) among the front and rear axles, as well as vectoring torque side to side, as traction conditions require, according to Merchant. She predicts a 30-40% take-rate on the AWD model.
During our early test driving in southern California, the XTS never felt lacking for power, although when pushed hard on the more extreme canyon roads the limits of 304 hp propelling a two-ton vehicle became apparent. EPA-rated fuel economy is estimated at 17 city/28 highway mpg for the front-drive XTS. All-wheel-drive models are expected to achieve 17/27 mpg.
GM body engineers developed an all-steel body-in-white, with the exception of an aluminum hood, for XTS. The body has a high percentage of ultrahigh-strength alloys, according to Bill Peterson, the XTS Performance Manager. The front fenders are “significantly reinforced,” he explained, to support the car’s large adaptive-headlamp modules and to meet various global front-impact safety requirements. “We also increased the amount of structural adhesive in the front end to help stiffen up the structure to meet offset and barrier tests,” Peterson told AEI.
Overall body craftsmanship, as evidenced by consistent 3- to 4-mm (0.12- to 0.16-in) closure gaps, was superb on the fleet of XTSs used during the media preview AEI attended in May.
XTS Interior Design Chief Christine Park (who became Cadillac’s Exterior Design Manager last spring) praised the XTS body-engineering team for its proactive collaboration that she said “really helped us execute many new ideas inside the cabin.” She noted that the car’s head-up display is mounted flush in the top of the instrument panel, which effectively hides the projector. Also, Park credited the engineers for creating a long, one-piece seamless bright-trim strip, requiring a significant tooling investment, which contributes to the complex cockpit’s eye-pleasing, high-quality appearance.
GM invests in chassis sophistication
The XTS’s chassis and suspension package includes standard Magnetic Ride Control, HiPer Strut front suspension, rear air springs, and front Brembo brakes.
The so-called HiPer strut unit uses a dual-path top mounting to separate spring and damper loads to the strut body. This is claimed to reduce torque steer while also improving ride and steering. Our brief early driving experience showed the XTS to have a segment-appropriate combination of ride comfort and chassis-motion control.
The hydraulic steering-assist system features Nexteer Automotive’s Magnasteer magnetorheological variable assist. This nicely weighted system, as configured in the XTS, delivers (in the author’s view) one of the best combinations of steering feel and transition in the large-luxury segment. The XTS steers well indeed for a large luxury car.
In terms of braking, GM has been increasing its business with Italian premium brake-system supplier Brembo. XTS and ATS both sport Brembo foundation brake sets.
“We debated the level of cost vs. performance vs. price, but [GM North America President] Mark Reuss is pushing all the vehicle teams to make GM a leader in braking system feel and performance,” said Hampden Tener, Cadillac Product Planning Director. “The engineers concluded the Brembo system satisfies our many requirements.”
Convergence of radar, camera-based systems
Cadillac is introducing new short- and long-range radar systems with the XTS. These systems are key to the merging of driver awareness/driver assistance technologies, noted Bill Peterson. They will be used for adaptive cruise control, rear cross-traffic alert, and front and rear automatic braking—a concept GM engineers describe as serving as “virtual front and rear bumpers.”
The radar package is being rolled out in phases. “The long-range and medium-range radars for adaptive cruise are coming later in 2012,” Peterson told AEI. “The upcoming package is something you really have to get right—it can’t issue false alerts and needs to be cadenced to a proper road-test vehicle,” he said while noting the system’s ongoing development.
The XTS package includes a front-facing camera, a rear backup camera, and a radar mounted in each rear quarter panel.
The XTS’s Driver Awareness Package and Driver Assist Package include the aforementioned Safety Seat Alert along with: forward collision alert system based on radar and camera technology; the camera and radar-based adaptive cruise control; camera-based lane-departure warning that activates at speeds above 35 mph (56 km/h); radar-based side blind-zone alert; radar-based cross traffic alert; adaptive forward lighting with projector headlamps that swivel in the direction of the front wheels; and rear vision camera with dynamic guidelines display.
The front and rear automatic braking system uses the car’s radar combined with ultrasonic sensors. In stop-and-go traffic, the system will alert if the lead vehicle slows unexpectedly and, if necessary, apply the brakes to reduce speed or help prevent an impact. In addition, the car’s brake-assist uses the radar/camera array to automatically apply added brake force to help slow the vehicle more quickly.
“XTS is quite an accomplishment,” concluded analyst Jackson of IHS Automotive. “Executed under incredibly tight timing constraints, GM has arrived with a very competitive product. XTS offers a lot of opportunity to really help the Cadillac brand and certainly bolster share within the overall market, and do so very profitably.”