The Cadillac STS is given an overall "Good" score in the Insurance Institute for Highway Safety frontal crash test. And an "Acceptable" rating in the side impact test. In the side impact test injury measurements to the driver's pelvis was rated "Poor" and for the torso "Acceptable."
The front wheel drive Seville was retired in 2004, replaced by an entirely new STS model based on the rear wheel drive GM Sigma platform. All wheel drive is offered as an option, the first Cadillac sedan to be available with this drive system. The STS carries on the Magnetic Ride Control suspension, which has bragging rights as being the 'fastest reacting suspension ever,' before it was ever utilized on newer Corvettes and Ferraris.
The Cadillac STS is assembled at GM's Lansing Grand River facility in Lansing, Michigan along with the smaller Cadillac CTS sedan and Cadillac SRX crossover SUV.
As of 2007, engines are a 3.6L High Feature LY7 V6 with 255hp (190kW) and 252lb·ft (342N·m) and the 4.6L Northstar LH2 V8 which puts out 320hp (239kW) and 315lb·ft (427N·m) in the STS. All engine models feature dual overhead camshafts with VVT. Remote ignition is standard. Although most 2005 and 2006 Cadillac STS models offer a 255hp (190kW) engine, an option for a 3.6L 320hp (239kW) engine was available at the time through Cadillac's performance packages. As of 2007, Cadillac now has different packages and car models, which no longer support this option.