The Cadillac STS is powered by a V8 engine in its standard configuration, and there was no factory V6 option offered for the model. The high-performance STS-V variant uses a different V8, not a V6.
Engine options in the STS lineup
To understand the STS’s powertrain, it helps to outline the two main engines that defined the lineup during its production years.
- 4.6-liter Northstar V8 — standard powerplant in the base STS
- 4.4-liter supercharged Northstar V8 — powering the STS-V
In all configurations, the STS family relied on V8 powertrains rather than a V6 option, underscoring its luxury and performance positioning.
Is there a V6 option?
No. The STS did not offer a factory V6 engine. Cadillac designed the model around V8 power, with the STS-V continuing that V8-based performance focus.
Notes on the STS-V
The STS-V represents the performance-focused variant of the line, featuring a supercharged V8 that delivers significantly more output than the standard STS. Both versions share the same V8 layout, differentiating themselves from rivals that offered V6 options in similar luxury sedans.
Summary
Short answer: The Cadillac STS is a V8-powered sedan. The base model uses a 4.6-liter Northstar V8, while the STS-V uses a 4.4-liter supercharged V8. There was no V6 option for the STS lineup.