There are 3 stored owner reports matching the fuel system leading-label group for the 2005 Mercury Mariner in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 3 of 3 matching reports.
Open the full vehicle complaint log (all categories)WHILE STOPPED, THE ACCELERATOR PEDAL STICKS IN THE "UP" POSITION, AND REQUIRES EXCESSIVE FORCE TO MOVE THE VEHICLE. THIS SOMETIMES RESULTS IN EXCESSIVE ACCELERATION WHEN THE PEDAL BECOMES UNSTUCK. *TR
GAS MILEAGE HAS SUDDENLY AND MARKEDLY PLUMMETED ON HIGHWAY DRIVING. AIR FILTER REPLACED - NO CHANGE. THERE HAS BEEN NO CHANGE IN DRIVING PATTERNS. IT HAS GONE FROM AROUND 20 HWY TO AROUND 10 HWY OUT OF THE BLUE - NO ENGINE/TRANNY/BRAKES ISSUES OR ANYTHING LIKE THAT. NOT A CLUE. *TR
FUEL MILEAGE FOR 2005 MERCURY MARINER IS NOT EVEN CLOSE TO WHAT IS STATED ON WINDOW STICKER. I COMPLETELY UNDERSTAND THAT DRIVING HABITS AND CONDITION APPLY, BUT WHEN THE WINDOW STICKER READS 22 LOCAL 26 HWY AND YOUR ACTUAL IS 16 HWY, THERE IS SOMETHING WRONG. THE CAR HAS BEEN TO THE DEALER ON A REGULAR BASIS AND EACH TIME I HAVE COMPLAINED. THEY DO THERE OWN TEST AND STATE THE TRUCK IS GETTING 22 MPG. I DO ALL HIGHWAY DRIVING ON A RELATIVELY FLAT SURFACE ALL WEEK LONG AND ONLY GET 16 MPG. THE TAIL PIPE IS FULL OF SOOT AND THE DEALER STATES NO PROBLEM. *NM
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Apr 28, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.