Engine choices include a V-6 or a V-8, and all-wheel drive is a $1,900 option with either engine. I drove an all-wheel-drive V-6 Luxury model whose base price was $41,740.
Although the V-6 cranks out less power than the V-8, it has a reasonably flat power band, is free from vibration and is a perfect companion to the five-speed automatic transmission. The automatic can be shifted manually, which is nice for spirited driving.
The all-wheel drive makes perfect sense for many buyers because it gives enhanced traction in rain and snow. Plus, it puts Cadillac in contention with Audi, Acura, BMW, Infiniti and Mercedes-Benz because they offer all-wheel drive.
The STS is available with numerous options, such as a navigation system, Bose 5.1 surround-sound system, heated and cooled ventilated seats, adaptive cruise control, head-up display, heated steering
wheel and a remote start.
For 2006, the Bose sound system and navigation are standard on the V-8 with the 1SE package. Stealth Grey, Radiant Bronze, Blackberry and Infrared are new paint colors.
The STS is composed, confident and comfortable in the same way as the leading imports. The body panels fit tightly, with small gaps around the doors and hood.
"The new STS is the best we've ever done," said Mark LaNeve, Cadillac general manager, when the car was shown to auto writers in August. After driving one for a week, I concur.
The STS is built on the Sigma platform that is also used for the smaller CTS. According to Cadillac, the 254-horsepower, 3.6-liter V-6 hits 60 miles per hour in about seven seconds. The 320-horsepower 4.6-liter Northstar V-8 does the same in 5.9 seconds. Both engines have variable valve timing, oil-life monitoring and a five-speed automatic transmission. They don't need a tuneup until 100,000 miles. Cadillac expects about 70 percent of sales will be the V-6.
Dave Leon, chief engineer, said the STS was designed to ride and handle like a European car. It also had to be quiet and luxurious, he said. To reach that goal, Cadillac engineers spent time developing the handling at the Nurburgring racetrack in Germany. The STS is 448 pounds lighter than a BMW 7-series, thanks to the use of high-strength steel and aluminum. Leon said the STS is as agile as a BMW 5-series while being as big as the 7-series.
Another goal was to make the STS quiet, with just enough of the right sounds to give the car character. Triple door seals, structural foam in the pillars, laminated acoustic glass and a laminated steel firewall contribute to a peaceful cabin.
The interior is classy and understated. The gauges are subtle and restrained. The instrument panel looks as if it could be from a Lexus. The leather-like texture is handsome, and brushed aluminum on the center stack surrounds the audio and climate control units. Simple knobs and flat buttons are easy to operate, although slightly larger knobs would be better for gloved hands in cold weather.
Back-seat legroom is not as generous as one expects in a car with a 116.4-inch wheelbase.
The STS ride is supple yet firm. Aluminum is used in both the front and rear independent suspension. The multilink rear unit is mounted on a subframe that isolates the body from road noise.
The optional Magnetic Ride suspension uses valveless shock absorbers with fluid that contains suspended iron particles. Electric current to the shock absorber changes the viscosity of the fluid to make the shock soft or firm. The changes occur in milliseconds. At 60 miles per hour, the suspension can change from full soft to full firm in the time it takes the wheel to travel three inches. Magnetic Ride is terrific in its ability to provide comfort and handling without compromising either.
Cadillac is serious about redefining itself, and the STS is a great road map to the future.
The base price of the test car was $41,740. The optional luxury package included memory seats, power lumbar support, heated seats, rain sensing wipers, 17-inch polished aluminum wheels and a power sunroof. All-wheel drive added $1,900. Premium paint and performance four-wheel anti-lock disc brakes brought the sticker price to $47,670.
Four years or 50,000 miles.
Engine: 3.6-liter, 254-hp V-6
Wheelbase: 116.4 inches
Curb weight: 3,660 lbs.
Base price: $41,740
As driven: $47,670
Mpg rating: 17 city, 25 hwy. At A Glance
Point: With all-wheel drive and a V-6, the STS is the most European Cadillac yet. It pairs responsive handling with a quiet, refined cabin that has the fit and finish of some of the best from Japan. A Northstar V-8 is optional.
Counterpoint: The understated exterior styling may be a little too plain. The outside mirrors are fairly small, and rear-seat legroom could be better considering the size of the vehicle.