Premium midsize car; Built in USA
  • 4-door sedan
  • longitudinal front-engine/rear- or all-wheel drive
Good condition price range: $9,500 – $33,500*

2005 Cadillac STS

2005 Cadillac STS

2005 Cadillac STS

2006 Cadillac STS

  • Acceleration
  • Handling/roadholding
  • Rear-seat room

This Cadillac impresses dynamically, and the availability of all-wheel drive and a bona fide high-performance STS-V edition are assets. AWD is a pricey proposition on V8 models, however, so kudos to Cadillac for making it a stand-alone option on V6s. Inside, STS disappoints with subpar rear-seat space and materials that are not in step with class pacesetters. On any model, extra-cost items can add quickly to the price, making an intelligently optioned V6 version the best value in this line.


Cadillac launched a new midsize luxury sedan for 2005, replacing the front-wheel-drive Seville with the STS, which came with rear- or all-wheel drive. Basically a stretched version of Cadillac’s premium midsize CTS sedan, STS was 4.7 inches shorter than Seville, but an inch taller and a sizable 4.2 inches longer in wheelbase. STS offered a 255-hp V6 with rear-wheel drive or a 320-hp V8 with rear- or AWD. The sole transmission was a 5-speed automatic with manual shift gate. Antilock 4-wheel disc brakes and traction/antiskid control were standard. So were front side airbags and curtain side airbags. OnStar assistance was also included. Adaptive cruise control was an option that could be teamed with a four-color head-up instrument display. Also available were heated/cooled front seats and a touch screen navigation system with voice recognition. A $13,115 Preferred Equipment package includes performance tires and steering. It also included GM’s Magnetic Ride Control with shock absorbers that automatically adjust firmness within Touring and Sport settings to match the road surface. Performance-tread 18-inch tires and uprated brakes could be ordered in a Performance Handling package.

Yearly Updates

2006 STS
Cadillac made all-wheel drive available as a stand-alone option for 2006 V6 models. A high-performance STS-V with a 469-hp supercharged V8 engine also joined the lineup.
2007 STS
All V8 versions of Cadillac’s STS sedan got a 6-speed automatic transmission for 2007.
2008 STS
The 2008 Cadillac STS got updated styling and a more powerful V6 engine. V6 models got a 302-horsepower 3.6-liter engine, an increase of 48 hp for ’08. A lane departure and blind-spot alert system were newly available for 2008.
2009 STS
STS received no major changes following its 2008 freshening.
2010 STS
The 2010 Cadillac STS was largely unchanged, though a high-performance model was discontinued.
2011 STS
The 2011 Cadillac STS lineup is revised, as the Base trim level is joined by the mid-level Luxury Collection and top-end Premium Collection. The V8 engine has been discontinued.


longitudinal front-engine/rear- or all-wheel drive

STS V6 models come with a 254-hp 3.6-liter engine. V8s have a 320-hp 4.6-liter engine. Both engines team with a 5-speed automatic transmission. STS-V has a 469-hp 4.4-liter V8 and a 6-speed automatic. Both automatics have a manual shift gate. For 2008, V6 models had a 302-horsepower 3.6-liter engine, an increase of 48 hp.

dohc V6
Engine Size (liters/cubic inches) 3.6/217
Engine HP 254-302
Engine Torque (lb-ft) 252
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
5-speed automatic



dohc V6
Engine Size (liters/cubic inches) 4.6/278
Engine HP 320
Engine Torque (lb-ft) 315
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
5-speed automatic



dohc V8
Engine Size (liters/cubic inches) 4.4/267
Engine HP 469
Engine Torque (lb-ft) 439
Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested
6-speed automatic


Road Test

Base V6 and V8 models furnish brisk takeoffs, with the V8 showing stronger highway-speed passing response. Cadillac estimates 7.0 sec 0-60 mph for the V6, 5.9 for the base V8, and 4.8 for the muscular STS-V.

Rear-drive V6 models averaged 14.7-16.2 mpg depending on driving conditions. AWD V6 test car averaged 17.7. Test rear-drive V8s averaged 15.2-17.5. We have not had an opportunity to measure with the STS-V.

Models equipped with the base suspension and 17-inch tires offered the best blend of ride comfort and composure. The STS-V is nearly as composed as these versions. Models equipped with the performance handling package trigger some jitter on rough roads.

STS-V is the best-handling model in the lineup, with moves nearly as sharp as its top German rivals. Other versions are less athletic, but still are composed overall. Some testers complain of overassisted steering and numb on-center feel.

The cabin is generally serene. Engines sound refined during acceleration, with wind and road noise well-suppressed. While assembly is generally good, materials quality is not up to European or Japanese rivals. The available navigation system absorbs, and therefore complicates, audio adjustments.

While the front seats offer good head and leg room, a wide center console and high windowsills make some testers feel “hemmed-in.” A standard power tilt/telescope steering wheel is a driver-comfort plus. Though larger than Cadillac’s CTS, the rear seat is short on leg room overall and head room with the available sunroof. Cargo capacity is nothing special in STS. A small opening limits the ability to load larger items, and in-cabin storage is merely average.


Model Tested: 2005Cadillac STS V6

Ratings values are on a 1-10 scale, with 10 being the best. With the exception of Value, these numbers reflect how the vehicle compares against the universe of vehicles, not just against rivals in its class.


Acceleration - 7
Fuel Economy - 4
Ride Quality - 8
Steering/Handling - 7
Quietness - 8


Controls/Materials - 7
Room/Comfort Front - 7
Room/Comfort Rear - 5
Cargo Room - 3


Value - 6

Total: 62


4-door sedan
Wheelbase (in.) Length (in.) Width (in.) Height (in.) Weight (lbs)
116.4 196.3 72.6 57.6
Cargo Volume (cu/ft) Payload Capacity (cu/ft) Fuel Capacity (gal.) Seating Capacity
13.8 17.5 5
Headroom Legroom
Front Rear Front Rear
38.7 37.9 42.6 38.3
Safety Ratings

Model Tested: N/A


(5 is the highest rating)

Front Impact Test

Driver Injury - N/A
Front Passenger Injury - N/A

Side Impact Test

Driver Injury - N/A
Rear Passenger Injury - N/A


(A score of 100 is average. Lower is better)

Collision N/A
Injury N/A
Theft N/A

Trouble Spots

Fuel gauge
Description: The engine may not start or may stall because the tank is empty yet the gauge shows fuel remaining, or the fuel gauge will not show full after refilling due to sulfur corrosion of the fuel level sender and if after treating with Fuel System Cleaner PLUS the problem remains, the sender may need to be replaced. (2005-06)
Oil leak
Description: Oil leaks at the timing cover on 4.6L engines may require a gasket or a new timing cover. (2004-05)
Oil leak
Description: Oil leaks develop on the lower area of 4.6L V8 in the area of the oil distribution plate. (2004-08)
Audio system
Description: Radio reception may be poor or have static because the rear window defogger may have invisible cracks in the grid lines. (2005-06)
Description: Paint on the hood blisters and bubbles, requiring refinishing and repainting. (2005-06)
Electrical problem
Description: A voluntary recall was issued to reprogram the PCM on some high-feature 3.6L engines. (2005)
Electrical problem
Description: The DVD monitors in the front seat headrests may quit working because the video feed cable comes loose requiring installation of cable clamps. (2005-08)
Electrical problem
Description: When using a portable music player (e.g. iPod) there may be noise in the car’s speakers whenever the vehicle’s power adapter is used and a ground loop isolator (from Radio Shack) is required between the device and the power outlet to prevent the noise. (2005-07)
Description: Fluid may leak from the rear differential requiring the original vent cap be replaced with a vent hose. (2003-07)

Recall History

2005 STS
Description: Some vehicles may have a left or right rear suspension toe link that could separate because of an incorrect weld, causing the affected rear wheel to turn unexpectedly. Dealer will replace the toe link and perform a wheel alignment.
2005-06 STS
Description: Some 2005 and 2006 STS models equipped with the V6 engine may have an inaccurate fuel gauge that won’t warn drivers when they are low on fuel. Dealer will reprogram the vehicle’s electronic control module (ECM) with new software.
Description: The rear axle pinion seal may experience a fluid leak. Dealers will replace the pinion seal.
2006 STS
Description: Some models equipped with all-wheel drive and the V6 engine may have faulty electronic throttle control software that could cause unwanted acceleration. Dealer will reprogram the ECM with new software.
2008 STS and STS-V
Description: The tire pressure monitoring system is inoperative, and, as such, does not conform to a Federal standard. Dealers will reprogram the remote-control door-lock-receiver module.

Equipment Lists

Equipment lists are only viewable on larger screen sizes.


Used-car pricing varies widely depending on local market conditions. Therefore, we recommend visiting websites that list used cars for sale to get a better idea of what a specific model is selling for in your area.