NHTSA lists 4 safety recalls and 141 owner complaints for the 2006 Cadillac STS. Most complaints involve air bags (58) and electrical system (21). The EPA rates it 17–19 mpg combined.
General Motors LLC (GM) is recalling certain model year 2004-2007 Cadillac CTS-V vehicles manufactured October 6, 2003, to March 15, 2007, and 2006-2007 Cadillac STS-V vehicles manufactured June 23, 2005, to March 15, 2007. In the affected vehicles, the electrical terminals of the fuel pump module may overheat resulting in the melting of the flange material.
ON CERTAIN PASSENGER VEHICLES, THE REAR AXLE PINION SEAL DOES NOT MEET ALL OF THE SPECIFICATIONS AND MAY EXPERIENCE A FLUID LEAK.
CERTAIN VEHICLES EQUIPPED WITH V6 ENGINES MAY HAVE A CONDITION WHERE FUEL IS NO LONGER SUPPLIED TO THE ENGINE. THIS CONDITION OCCURS WITHOUT THE ILLUMINATION OF THE FUEL LEVEL LOW INDICATOR LIGHT OR THE WARNING CHIME.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
“I UNDERSTAND THAT 2006 CADILLAC CTS HAS A RECALL FOR AIRBAG PROBLEMS. CADILLAC DOESN'T DENY THAT THE SAME SYSTEM WAS USED IN THE STS. I'VE SEEN SEVERAL COMPLAINTS ABOUT THE SAME PROBLEM. I JUST WONDER WHY THE STS WAS NOT RECALLED. I KNEW THERE WAS NO WARRANTY, AND THAT'S WHY I CONTACTED CADILLAC. KNOWING THIS THEY SENT ME FOR A DIAGNOSTIC, WHICH WAS A WASTE OF TIME AND MONEY. THE END RESULT WAS THAT THEY SAID IT'S NOT UNDER WARRANTY. I WOULD JUST LIKE YOU TO INVESTIGATE TO SEE IF THERE SHOULD BE A RECALL. THIS IS A SAFETY ISSUE THAT CADILLAC SHOULD ADDRESS. *JS”
“MY CAR HAS BEEN DIAGNOSED AS HAVING 'EXTENDED CRANK'. MY LOCAL CHEVY DEALER MADE APPROXIMATELY FIFTEEN ATTEMPTS AT FIXING IT TO NO AVAIL. I'M TOLD IT'S THE CHECK VALVE, BUT I HAVE NOT HAD THAT DONE BECAUSE ALL ATTEMPTS BY THE DEALER DIDN'T WORK; E.G., NEW COMPUTER (AND REMOVED), BATTERY (AND REMOVED), FUEL PUMP, ETC. VERY FRUSTRATING AND I FEEL IT'S A MATTER OF HEALTH AND SAFETY BECAUSE THE CAR ALMOST NEVER STARTS ON THE FIRST ATTEMPT, AND SOUNDS LIKE IT'S A DEAD BATTERY.”
“PURCHASED 2006 CADILLAC STS BUILT ON JUNE 21 2005 LAST DAY OF 2005 MODEL. CAR HAS HAD ALL THE ISSUES THAT 22005 VEHICLE HAD. JUNE 23RD 2005 WAS FIRST DAY OF PRODUCTION. AT EVERY CORNER VIN # ARE NOTED HOWEVER FOR THIS MODEL THE BUILD DAYS WHICH NOTED BY CADILLAC ARE THE IMPORTANT FACTORS. I DON'T THINK COINCIDENCE THAT I'VE BEEN COMPANLING TO CADILLACAND ASKING FOR HELP WITH ZERO HELP. CATALYTIC CONVERTER WAS EXTENDED WARRANTEE FOR 200000 AND 12 YEARS HOWEVER CADILLAC ALWAYS SAYS VIN EVEN THOUGH DATES ARE THE ONLY THING NOTED. I HAVE CALLED AND E,AIL FOR 3 YEARS. MY CAR IS OFF ROAD AND THEY HAVE REFUSED TO LOOK AND EVEN IF I PAID THEY WOULDN'T GUARANTEE THEY WOULD EVEN LOOK AT THE ISSUES. MY CAR IS IN ABSOLUTE LIMBO NEITHER A 2006 OR 05 OR WHATEVER. THEY HAVE REFUSED EVERY STEP EVEN THOUGH IT WAS BASED ON RECALLS”
Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.
| Version | City | Hwy | Comb. | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|
| STS Auto (S5), 6 cyl, 3.6 L · Rear-Wheel Drive | 16 | 25 | 19 | $3,300 | 468 |
| STS Auto (S5), 8 cyl, 4.6 L · Rear-Wheel Drive | 15 | 24 | 18 | $4,300 | 494 |
| STS AWD Auto (S5), 6 cyl, 3.6 L · 4-Wheel or All-Wheel Drive | 15 | 23 | 18 | $3,450 | 494 |
| STS AWD Auto (S5), 8 cyl, 4.6 L · 4-Wheel or All-Wheel Drive | 14 | 21 | 17 | $4,550 | 523 |
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
4 safety recalls as of Nov 11, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
Owners filed 141 complaints with NHTSA. The most-cited components are air bags (58), electrical system (21), engine (20). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.
The EPA rates the 2006 Cadillac STS at 17–19 mpg combined, depending on engine and drivetrain (4 versions rated).