- Gas
- Midsize cars
- MY2005–2011
Cadillac STS MPG & Fuel Cost by Year
7 model years · 2005–2011
15,000 mi/yr · regular gasoline $4.36/gal (U.S. average, Sep 2026)
Cadillac STS fuel economy at a glance
EPA has rated the Cadillac STS for 7 model years, 2005 to 2011. Across those years its combined rating runs 16–21 MPG. The latest model year, 2011, has 2 configurations rated 21 MPG combined and costing $3,110–$3,130 a year to fuel at regular gasoline $4.36/gal (U.S. average, Sep 2026). The most efficient configuration on record since 2005 is the 2011 STS 3.6L 6-cyl RWD, at 21 MPG.
Cadillac STS MPG by year
| Year | Gas (MPG) | $/yr |
|---|---|---|
| 2010-2011 Generation page | ||
| 2011 | 21 | $3,110–$3,130 |
| 2010 | 17–21 | $3,110–$3,840 |
| 2008-2009 Generation page | ||
| 2009 | 17–20 | $3,270–$4,730 |
| 2008 | 16–20 | $3,270–$5,020 |
| 2007 Generation page | ||
| 2007 | 16–19 | $3,440–$5,020 |
| 2005-2006 Generation page | ||
| 2006 | 17–19 | $3,440–$4,730 |
| 2005 | 17–18 | $3,630–$4,730 |
Costs use the current EIA price set and 15,000 miles a year for every year, so years are comparable. Green marks the best year for each powertrain.
Cadillac STS generations
4 generations between 2005 and 2011. Open one for the table of every model year and configuration.
2011 powertrain options
More Cadillac models
Frequently asked questions
What is the Cadillac STS's gas mileage by year?
EPA combined ratings for the Cadillac STS run 16–21 MPG across model years 2005 to 2011. The latest year, 2011, is rated 21 MPG.
Which Cadillac STS model year has the best gas mileage?
The 2011 Cadillac STS STS 3.6L 6-cyl RWD has the highest combined rating since 2005, at 21 MPG.
How much does a Cadillac STS cost to fuel per year?
For MY2011, EPA-rated configurations cost $3,110–$3,130 a year to fuel, driving 15,000 miles at regular gasoline $4.36/gal (U.S. average, Sep 2026). The most efficient one costs $3,110.
Has the Cadillac STS's fuel economy improved over time?
Yes. The most efficient configuration moved from 18 MPG in 2005 to 21 MPG in 2011, 3 MPG more.