The 2005 Cadillac STS is the luxury nameplate’s all-new luxury performance sedan. It has been designed, engineered and executed to deliver precision craftsmanship, outstanding performance, and sophisticated luxury in a distinctly American package.
Based on General Motors’ new rear-wheel-drive Sigma architecture, which also is the foundation for Cadillac’s entry-luxury CTS sedan, CTS V-series high-performance sedan, and SRX luxury performance utility – the STS is designed to compete head-on with world-renowned prestige sedans in markets around the globe.
“Our long-term goal for Cadillac is to become the Standard of the World once again,” said Mark LaNeve, general manager for Cadillac. “In order to succeed globally, we have to build vehicles that have outstanding performance, exceptional quality and reliability, and meet the demands of the most discerning car buyers. “The STS represents the latest step in that direction.”
From its Cadillac-signature bold exterior styling to its outstanding power and road capabilities, the STS is the product of unwavering attention to detail. More than 1,000 criteria points have been strictly adhered to throughout development of the vehicle. The result is outstanding fit and finish, overall harmony, refined performance and purposeful innovation.
The 4.6-liter Northstar V-8 is a 90-degree DOHC four
-valve-per-cylinder engine, with an aluminum block and cylinder heads and valve train with roller finger followers. The Northstar is equipped with a host of technologies, including:
* Four-cam continuously variable valve timing (VVT) for improved performance, refinement, economy and emissions.
* Electronic throttle control, providing additional driving refinement. This allows the engine control system to precisely and seamlessly tailor vehicle performance to the driver demands.
* Low restriction intake and exhaust manifolds and cylinder head ports designed to ensure optimum airflow and cylinder-to-cylinder distribution for maximum performance and emissions control.
* Close coupled catalytic converters, mounted directly adjacent to the exhaust manifolds. They reach effective operating temperature more rapidly after engine start.
* New air induction system, redesigned for enhanced capacity and noise attenuation. It features tuned resonators, additional resonators in the clean air duct and use of isolator pads in the clean air duct mounting.
* Powerful engine control module (ECM) and high-speed communication system dedicated to engine control. An extremely powerful, state-of-the-art ECM, with a 16-bit, 24 MHz dual microprocessor, high memory capacity, and a redundant “safety” processor backing up the ETC enables the Northstar engine to provide its advanced capabilities. A transmission control module (TCM) controls the transmission with inputs from the ECM.
* Polymer-coated pistons and cast-iron exhaust manifolds to further reduce noise, vibration and harshness.
* A forged steel crankshaft delivers additional stiffness for better noise, vibration and harshness performance; ensures the durability required of high specific output variants; and provides an extra degree of robustness.
Rear Wheel Drive
Rear-wheel-drive STS offerings offer an available limited slip differential, which mechanically limits wheel spin on all surfaces for improved vehicle performance during handling maneuvers.
Vehicles equipped with the V-8 engine are available with three final drive ratios configurations; 2.73 for enhanced fuel economy; 3.23 for mid-sport performance; and a 3.42 for optimized performance. Exported vehicles are only equipped with the 3.42 final drive.
All Wheel Drive
Vehicles equipped with all wheel drive (V-8-equipped vehicles only) have a final drive ratio of 3.23. The system incorporates a 40/60 rear bias torque split to provide the STS with superior handling performance, acceleration, traction, and control for dry, wet, icy, and snowy road conditions. Its three open differential layout, coupled with four-wheel traction control, balances driving torque distribution to each wheel and minimizes wheel spin to optimize on-road performance.
Electronically Controlled Transmissions
The V-8 is mated to electronically controlled five-speed automatic transmissions – the Hydra-Matic 5L50-E is mated with the V-8. The ransmission incorporates Driver Shift Control (DSC) and Performance Algorithm Liftfoot (PAL) technologies.
Driver Shift Control enables the driver to switch from automatic to a clutchless five-speed high-performance manual transmission. Once the driver moves the gearshift lever into DSC mode, a quick tap is all that is required for smooth, crisp upshifts or downshifts within a selected range.
Performance Algorithm Liftfoot inhibits upshifts while maintaining engine braking following continuous performance driving. The transmission control module (TCM) monitors driver behavior to determine whether or not to enable this feature. For example, if the system detects a drop in vehicle speed prior to entering a turn or a lane change, up to two downshifts can occur to provide the driver with maximum vehicle performance.
Like its CTS, SRX, and XLR siblings, the all-new 2005 Cadillac STS stands alone as the distinctly bold offering of luxury and style in its competitive set.
However, while the STS carries the design vocabulary, heritage cues and styling characteristics found throughout the Cadillac product portfolio, it does so in a manner that is refined and sophisticated. It is intentionally crafted to meet the discriminating tastes and demands of the segment in which it competes – the most discerning buyers in the automobile marketplace.
The exterior fit and finish on the STS is taking Cadillac to the next level of refinement and exemplifies the attention to detail seen throughout the vehicle. Body and exterior dimensions are precisely executed. Radii on major body components, such as the hood and decklid, are tight and contribute to its crisp exterior appearance. Doors-into-roof construction and a superplastic-formed aluminum decklid ensure a clean and refined exterior.
Overall, the STS is 196-inches long, 72.6 inches wide and 57.6-inches high, making it the largest sedan offering in the Sigma-based family. As a result, the STS delivers exceptional interior spaciousness for front and rear passengers alike. Front legroom, shoulder and head room are 42.6, 58.6, and 38.7-inches respectively; related rear passenger dimensions are 38.3, 54.4, and 37.9-inches. All are near or at the top of the STS’ competitive class.
Distinctive, bold exterior
At first glance, there’s no mistaking the STS as a contemporary Cadillac, with its vertically stacked headlamps and light-emitting diode (LED) tail lamps, signature LED CHMSL, airfoil grille, horizontal spline lines, and dihedral-shaped hood.
While its overall shape brings a faster profile and more rake than its CTS sibling, it’s done so in the context of elegance and grace. Doors-into-roof construction enables more tumblehome, the vehicle sides are sculpted inward, delivering a look of upscale rear-wheel-drive performance with a lower roof line, while maintaining a roomy interior. In addition, a wider tapering sail panel; lower, more sculptured hood; smoother wheel openings; and a tighter wheel-to-body relationship further communicate the agility of the STS, as well as sophistication and substance.
Seven-spoke 17- or available nine-spoke 18-inch wheels lead to larger, higher-performance calipers and rotors, leaving no doubt about the STS’ luxury performance competence. A wire mesh, electro-polished stainless steel lower grille reiterates the statement.
A wheelbase of 116.4-inches and front/rear track of 61.8/62.3-inches, combined with a flush wheel-to-body relationship, ensures well-grounded appeal and presence.
The rocker treatments on the vehicle are specific to the STS, bringing a more sculpted shape to the vehicle’s lower line for more presence and refinement. A single-piece fascia design, which eliminates seams for a clean, uninterrupted appearance, enables excellent fit and finish.
Vertically stacked headlamps, a traditional Cadillac cue, are slightly narrower and lower than what’s seen on the siblings of STS. The headlamps incorporate large, dual 70-millimeter projector lenses encased in an aluminized, single piece bezel.
LED tail lamps are designed with indirect optics, an industry-first application, and incorporate 30 sources of illumination per unit. The use of indirect optics eliminates “pinpoints” of light normally associated with LEDs and enables a very upscale, refined appearance when illuminated.
On the STS, each tail lamp has two vertical arrays consisting of 15 LEDs, and each LED has 20 optical facets. This configuration enables very precise illumination tuning and the design flexibility needed to meet domestic or export requirements.
The LED CHMSL on the STS is only 12-millimeters thick and consists of 78 points of illumination. An ingenious lens design incorporates the use of pillow optics, which again replaces a “pinpoint” appearance normally associated with LEDs with a smooth, refined output of light.
The rear portion of the STS is clean and uninterrupted, due in large part to a one-piece superplastic-formed aluminum decklid with an integrated pocket on the trailing edge for the LED CHMSL. Use of the superplastic forming process enabled integration of rear lighting elements without use of additional appliqués or trim.
Crafted, inviting interior
The interior of the STS is executed to extremely close and demanding tolerances, enabling a tight, well-crafted appearance throughout. Eucalyptus wood is found on the steering wheel, center console, instrument panel, and door armrests. Other finishes, such as in-mold processed aluminum (dent and mar resistant), are also used.
Premium surfaces are found throughout the interior, including dual-firmness Tuscany all-leather seats (available as heated and ventilated) that are specially tanned for a softer feel. Spray-skinned urethane/natural grained surfaces on the door and instrument panel ensure an inviting tactile touch, as do the headliner and interior pillars, which are soft backed and covered with a Monaco woven fabric.