Review

Introduction
When the Cadillac STS was redesigned and introduced as an all-new model last year, Cadillac delivered on the promise of the original Seville Touring Sedan: a car that people who like to drive will want to drive. For 2006, the game gets even faster with a new STS-V model that adds supercharged velocity to the grand touring.

The STS models benefit from GM's newest V6 and V8 engines, which boast the latest in computerized engine management and variable valve timing. The result is smooth, efficient power. The STS also offers a choice of equally smooth suspensions, from the standard suspension designed for smooth, comfortable commuting to an active suspension that instantly adjusts to any driving situation, whether cruising through a sea of potholes or swiftly motoring around a sweeping turn.

What really sets this latest generation of luxury models apart, however, is that the STS has returned to rear-wheel drive, an essential element for truly spirited driving. All-wheel drive is also available for handling stability in inclement weather.

STS is blessed with Cadillac's best interior ever, with comfortable but supportive seats that are infinitely adjustable, ample storage space, and superior sound systems. Most important, state-of-the-art occupant safety is standard.

Cadillac's top management rolled the dice when it empowered its stylists and engineers to create the all-new STS. But they were right insisting it be designed and outfitted from the tires up with one goal in sight: a car meant to bring as much joy and pleasure to the driver as it does comfort and convenience to the passengers. The STS has shown there's plenty of life in the wreath and crest, while the new STS-V shows that a domestic sedan can run alongside the world's best.

Line-Up
The Cadillac STS comes with a choice of V6 ($41,020) or a V8 ($47,520) engines. They come with a five-speed automatic transmission. Rear-wheel drive is standard. All-wheel drive ($1900) is available for either model. The STS-V ($74,270) comes with a supercharged V8 and a six-speed automatic; all-wheel drive isn't available.

STS comes standard with leather trim, dual-zone automatic climate control, Bose AM/FM/CD stereo, the usual lineup of power creature comforts and driver aids, OnStar telematics (with one year's service), Stabilitrak electronic stability control, automatic headlamp high-beam control, and rear park assist.

The popular V6 Luxury Package ($2640) includes a Memory Package with dual eight-way power and heated front seats, power tilt and telescoping steering wheel with radio and climate control settings; four-way power front lumbar seat adjusters; an eight-speaker stereo with six-disc CD changer; rain-sensing wipers; polished aluminum wheels and memory for driver's seat, outside mirrors and steering wheel settings; offered as an add-on to this package are satellite radio, programmable garage door opener and eucalyptus wood interior trim ($730).

The V6 Luxury Performance Package ($8,285) adds 15-speaker surround-sound Bose stereo with in-dash six-disc CD changer, DVD-based navigation, Bluetooth phone interface, heated rear seats and ventilated/heated front seats, Eucalyptus wood trim, leather-wrapped wood-accented heated steering wheel, tilt/slide power sunroof, auto-dimming inside rearview mirror with OnStar controls, outside automatic recirculating air quality sensor, tire pressure monitoring system, universal home remote, decklid spoiler, and performance brakes; a heavy-duty cooling package ($150) can be added to this. Stand-alone options include a performance handling package ($795), Bose surround-sound stereo ($2,590), premium leather seats ($1,200), 18-inch polished aluminum wheels ($800), power moonroof ($1,200) and an engine-block heater ($100). Two of the nine exterior paints, Infrared and Diamond White, cost extra ($995).

The V8 Luxury Package ($4,445) includes the Memory Package, auto-dimming inside rearview mirror, heated front and rear seats, four-way power lumbar adjusters, Bose surround-sound stereo and navigation system, heated leather-wrapped steering wheel, universal home remote, and Eucalyptus wood trim. The V8 Luxury Performance Package ($10,740) adds an outside automatic recirculating air quality sensor, ventilated front seats, leather-wrapped wood-accented steering wheel, power sunroof, tire pressure monitoring system, more extensive Eucalyptus wood trim, Intellibeam Xenon headlamps and washers, a decklid spoiler, and performance brakes. The Premium Lux Performance Package ($12,790) adds premium Tuscany all-leather seating to the Luxury Performance Package list.

Adaptive cruise control ($2,300) is available for both models. A Performance Handling Package ($795) with special springs and shocks is available with rear-wheel drive but not all-wheel drive.

The STS-V comes with a higher level of standard equipment, including EZ Key with remote start, XM Satellite Radio, rear AV jacks, and rear obstacle detection, hand-wrapped leather surfaces with suede seat inserts, Olive Ash Burl wood and aluminum interior accents, rear climate system controls, and V-Series badging. Special paint and a sunroof are the only options.

Safety features that come standard on all models include dual two-stage frontal airbags, front seat mounted side airbags and front-and-rear side curtain airbags. Four-wheel anti-lock brakes are standard. Tire-pressure monitors are available only with the option packages.

Walk Around
The 2006 Cadillac STS is both new and familiar. It is strikingly dissimilar to its immediate predecessor, the 2003 Seville STS. The design of the STS, introduced as an all-new model for 2005, is the latest example of Cadillac's Art & Science design motif. Only the grille pretends to keep faith with any of the old Seville's softer, rounder shapes and lines.

Yet the STS is recognizable in its striking similarity to the CTS. The STS and CTS are indistinguishable to the casual observer even when parked side by side. Both cars present only minimally different iterations of the sharp angles and flat planes first seen in the Evoq concept. We now encounter examples of the Art & Science design theme almost daily in the SRX sport utility and XLR sports car. The now familiar theme can be seen to a lesser degree in the forward quarters of the new Escalade.

The similarity between CTS and STS runs deeper than the sheet metal. They both ride on the same platform. The wheelbase of the STS is only three inches longer than that of the CTS, and its body is six inches longer. The STS features much shorter overhangs (less metal hanging out over the front and rear wheels) than the old Seville. Besides better looks, this design makes for better handling and improved stability.

All that said, there's no mistaking the STS for anything but a Cadillac. Viewed head on, the trademark egg-crate grille and stacked headlamps are starkly functional in appearance. No wasted motion or volunteer excess there, to be sure.

From the side, the body's crisp lines draw an almost box-like silhouette that somehow still looks aerodynamic. Perhaps it's the gently curved A-pillar and C-pillar that tend a bit more toward art than science. Sharply contoured lower rocker panels tracking rearward from the front fascia's bottom edge pull the body down, adding a stylistic ground-effects look.

The backside is vaguely reminiscent of the old Eldorado coupe, with vertical taillights bracketing a tall, squared-off boot. Recessed in the boot's rear vertical is a trapezoidal inset, long enough for European-spec license plates, housing large backup lights at the left and right extremes. American-tradition dual exhausts exit below and at each end of the rear bumper. The optional rear spoiler, running the width of the trunk lid, adds stabilizing rear downforce without spoiling the look.

The performance STS-V is distinguished from the other STS models by its unique hood covering the supercharged powerplant, a larger, polished stainless steel wire-mesh front grille, a lower front fascia with a larger lower grille, brake ducts and splitter, lower side rockers, 10-spoke wheels, a higher rear spoiler, a lower rear fascia with wire-mesh accenting, and V-Series badging along with Supercharged badges on the doors.

Interior
The Cadillac STS cabin is warmer in appearance than the exterior, with soft leather surfaces complemented by warm wood accents. Those wood accents are not standard, but we much prefer them over the standard brushed aluminum trim, which looks and feels cold and reflects sunlight to the point of annoyance. Get the wood.

Seats are refreshingly supportive, for a Cadillac, without being overly firm. Arm rests and head restraints are a degree or two softer than the cushions and side bolsters, boosting the comfort factor a couple notches. All essential controls are within easy reach, although there could be more clearance between the lower door panels and seat bottom to access the front seat adjusters. For this reason, we were especially grateful for the seat memory feature, which often saved us from having to reach down there. The interior is roomy, fitting in between the marginally smaller CTS and externally larger 2003 Seville.

Instruments are easily scanned, white-on-black round analogs, with a large nested tachometer and speedometer between the smaller fuel and engine temperature gauges. The speedometer changes between English and metric electronically, so there's only one set of numbers around its circumference. Cruise control and running lights are managed via a stalk on the left side of the steering column, windshield wipers and washers with a stalk on the right. Buttons in the steering wheel spokes provide redundant controls for audio and driver information functions. A word of caution: the top-level stereo system, although delivering superb surround sound, is multi-tasked with a navigation system that, in combination, demands an extensive study of the owner's manual to operate with any degree of alacrity and confidence.

All four doors boast map pockets. The front center console is deep and wide and pre-wired for cellular and Bluetooth (to wirelessly tie the cell phone into the car's audio system allowing hand-free operation). The glove box, though, is barely sufficient to hold the navigation DVD case and owner's manual. Two cup holders are provided front and rear. The trunk is fully lined, with articulated, gas-pressurized struts.

Fit and finish are top grade, with notably tight interior trim tolerances. Careful attention was paid to reducing noise, vibration and harshness, with remarkable and commendable success. Specially laminated windshield and front door glass, wind tunnel-tuned outside mirrors and high-density/low-mass sound-deadening padding combine to deliver the quietest interior Cadillac's delivered in memory.

Driving Impressions
The Cadillac STS is everything it should have been from its inception, and more.

The 3.6-liter V6 engine generates 255 horsepower, the V8 produces 320 horsepower, and the new supercharged V8 delivers 469 horsepower, making it the most powerful engine ever produced for a Cadillac. The V6 does a more than adequate job of moving its 3,857-pound burden down the road. While the sound of the V6 isn't as robust or viscerally satisfying as that of the V8, it's nothing to be ashamed of either.

Except for the monster STS-V, the sportiest setup is the V8 with the optional performance handling package. Nudging the shift lever over to the right, into the manu-matic gate where the selected gear will hold all the way up to redline, and alternating between the accelerator and brake pedal allow frolicing at extremes heretofore beyond the reach of sedans wearing the wreath and crest. Cadillac's suspension engineers have finally demonstrated the difference between stiff and firm. Thankfully, all the sound filtering and deadening doesn't keep the V8's throaty exhaust note out of the cabin. Who needs a stereo with these tones to enjoy?

Then again, ordering the all wheel-drive with the Magnetic Ride Control supplementing the latest generation Stabilitrak is a hard package to top, though it adds some weight and isn't available with the handling package. Still, body lean in even the tightest switchbacks is almost non-existent, and mild whoop-de-doos barely give occupants' stomach a flip. Biasing 60 percent of the power to the rear wheels gives the all-wheel-drive STS the sporty dynamics of rear-wheel drive while sending enough power to the front wheels to pull the car through and out of corners with sureness and confidence.

The electronic steering is a delight, with the only shortcoming a slight softness on center. The car tracks well through corners, and turn-in is crisp, especially with the 18-inch, low-profile tires. The brakes are up to the car's potential, with a firm pedal and a feel that's more linear than not. Cadillac has ratcheted the Stabilitrak back a smidgen from its earlier aggressiveness, and it now waits a bit longer before stepping in. And when it does, it does so less abruptly, too. That's an improvement from a driving enthusiast's point of view because the electronic aids are less intrusive.

The 3.6-liter V6, 4.6-liter V8 and 4.4-liter supercharged V8 are GM's latest engines with double overhead cams, four valves per cylinder and variable-valve timing, or VVT. This latter system continuously varies valve operation to generate the most power from the least amount of fuel with the lowest emissions possible. Torque is what American drivers really use; torque is what gets a car moving in the first place, like when merging onto a freeway or passing on a two-lane. Recognizing that, Cadillac engineers designed the STS engines to generate lots of torque throughout the rev range for responsive performance at all engine speeds.

The V6 gets a dual-stage intake manifold that makes available 90 percent of the engine's 252 pound-feet of torque from 1900 to 5800 rpm. The V8 uses electronic throttle control, sometimes called drive-by-wire, to match the engine's performance to a variety of driver demands, from sedate highway cruising to rambunctious backroad motoring. The V8 generates 315 pound-feet of torque at 4400 rpm.

The STS-V's supercharged V8 pumps out 439 pound-feet of torque, with 90 percent of it delivered in a wide sweep of power from 2200 to 6000 rpm. This enormous power is delivered smoothly through the new six-speed automatic transmission. However, the performance upgrades found in virtually every dynamic element of the car, including larger tires and brakes, make the STS-V only suitable for those willing to sacrifice some comfort for a car that can jet from 0 to 60 mph in less than 5 seconds. There's also the STS-V's $2,100 gas guzzle tax to cons

Summary
The Cadillac STS may not threaten BMW's grip on the fun-to-drive crown, but it's definitely arrived when put up against Audi, Lexus and Mercedes-Benz, and the new V model is a credible thrust into BMW territory. People who enjoy getting where they're going as much if not more than being there but who pine for luxury touches and good ol' American V8 power need no longer compromise. Come on home.

New Car Test Drive correspondent Tom Lankard reported on the STS, with Greg Brown reporting on the STS-V.