Narrative:

I departed on VFR flight plan to ZZZ. Prior to departure; I advised the fueler to top off the aircraft fuel tanks. He added approximately 10 gallons to the tanks. At poh burn of approximately 8 gph and considering 38 usable gallons; we should have endurance for 4 hours 45 mins. After 3 hours 30 mins flight and approaching ZZZ from the west; the engine failed. I immediately pitched for best glide attitude and determined I could not land at ZZZ from the present distance and set up for landing on a nearby road. After performing the appropriate emergency procedures to no avail; the engine began running rough. I proceeded to ZZZ for landing. I declared an emergency and requested the crash fire rescue equipment equipment to stand by. On short base; the engine failed again and I glided to a power-off landing. Upon reaching the FBO and filling the tanks; I was shocked to learn that our total uplift was just over 40 gallons! Therefore; either the aircraft must be burning approximately 12 gph (150% of poh figures) or we were not completely full of fuel on departure. Factors influencing this event: although I monitored the fueling procedure; I did not doublechk the fuel level prior to flight; although I did sump the tank after the fueler left. While I was very clear that we needed a full tank of fuel; it is possible the fueler shorted us. Also; the cylinders in this aircraft were recently replaced; and it was still using mineral oil for this flight. This may have unduly increased the fuel burn as the engine is not fully 'broken in' yet. Perhaps there is a fuel leak somewhere in the system as may occur after an engine overhaul. Finally; though the fuel gauges were showing close to empty near the end of the 3 hour 30 min flight; I disregarded them as inaccurate; believing that I had at least 1 more hour worth of fuel endurance remaining. It is important to note that no injuries or property damage of any kind occurred from this event; I am well aware of the implications. I will check the tanks myself; especially before so long a flight and I will be more aware of the fuel gauge. Callback conversation with reporter revealed the following information: reporter stated that initially he believed the factory new engine to be the reason for a fuel high consumption. But after talking with other pilots and instructors; he has concluded that his own incorrect leaning procedures were the cause. He has not flown since this event and stated that he has taken it pretty hard because he worked diligently and considered himself to be a safe pilot. Now he doubts his abilities.

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Original NASA ASRS Text

Title: A LOW TIME C172 PLT FLYING A XCOUNTRY IMPROPERLY LEANED THE ENG'S FUEL MIXTURE; RESULTING IN FUEL EXHAUSTION. HE DECLARED AN EMER AND LANDED AT HIS DEST PWR OFF.

Narrative: I DEPARTED ON VFR FLT PLAN TO ZZZ. PRIOR TO DEP; I ADVISED THE FUELER TO TOP OFF THE ACFT FUEL TANKS. HE ADDED APPROX 10 GALLONS TO THE TANKS. AT POH BURN OF APPROX 8 GPH AND CONSIDERING 38 USABLE GALLONS; WE SHOULD HAVE ENDURANCE FOR 4 HRS 45 MINS. AFTER 3 HRS 30 MINS FLT AND APCHING ZZZ FROM THE W; THE ENG FAILED. I IMMEDIATELY PITCHED FOR BEST GLIDE ATTITUDE AND DETERMINED I COULD NOT LAND AT ZZZ FROM THE PRESENT DISTANCE AND SET UP FOR LNDG ON A NEARBY ROAD. AFTER PERFORMING THE APPROPRIATE EMER PROCS TO NO AVAIL; THE ENG BEGAN RUNNING ROUGH. I PROCEEDED TO ZZZ FOR LNDG. I DECLARED AN EMER AND REQUESTED THE CFR EQUIP TO STAND BY. ON SHORT BASE; THE ENG FAILED AGAIN AND I GLIDED TO A PWR-OFF LNDG. UPON REACHING THE FBO AND FILLING THE TANKS; I WAS SHOCKED TO LEARN THAT OUR TOTAL UPLIFT WAS JUST OVER 40 GALLONS! THEREFORE; EITHER THE ACFT MUST BE BURNING APPROX 12 GPH (150% OF POH FIGURES) OR WE WERE NOT COMPLETELY FULL OF FUEL ON DEP. FACTORS INFLUENCING THIS EVENT: ALTHOUGH I MONITORED THE FUELING PROC; I DID NOT DOUBLECHK THE FUEL LEVEL PRIOR TO FLT; ALTHOUGH I DID SUMP THE TANK AFTER THE FUELER LEFT. WHILE I WAS VERY CLR THAT WE NEEDED A FULL TANK OF FUEL; IT IS POSSIBLE THE FUELER SHORTED US. ALSO; THE CYLINDERS IN THIS ACFT WERE RECENTLY REPLACED; AND IT WAS STILL USING MINERAL OIL FOR THIS FLT. THIS MAY HAVE UNDULY INCREASED THE FUEL BURN AS THE ENG IS NOT FULLY 'BROKEN IN' YET. PERHAPS THERE IS A FUEL LEAK SOMEWHERE IN THE SYS AS MAY OCCUR AFTER AN ENG OVERHAUL. FINALLY; THOUGH THE FUEL GAUGES WERE SHOWING CLOSE TO EMPTY NEAR THE END OF THE 3 HR 30 MIN FLT; I DISREGARDED THEM AS INACCURATE; BELIEVING THAT I HAD AT LEAST 1 MORE HR WORTH OF FUEL ENDURANCE REMAINING. IT IS IMPORTANT TO NOTE THAT NO INJURIES OR PROPERTY DAMAGE OF ANY KIND OCCURRED FROM THIS EVENT; I AM WELL AWARE OF THE IMPLICATIONS. I WILL CHK THE TANKS MYSELF; ESPECIALLY BEFORE SO LONG A FLT AND I WILL BE MORE AWARE OF THE FUEL GAUGE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT INITIALLY HE BELIEVED THE FACTORY NEW ENG TO BE THE REASON FOR A FUEL HIGH CONSUMPTION. BUT AFTER TALKING WITH OTHER PLTS AND INSTRUCTORS; HE HAS CONCLUDED THAT HIS OWN INCORRECT LEANING PROCS WERE THE CAUSE. HE HAS NOT FLOWN SINCE THIS EVENT AND STATED THAT HE HAS TAKEN IT PRETTY HARD BECAUSE HE WORKED DILIGENTLY AND CONSIDERED HIMSELF TO BE A SAFE PLT. NOW HE DOUBTS HIS ABILITIES.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.