C182 PLT; AFTER FLYING A ROUND ROBIN TO AN ARPT 45 MINS AWAY; LANDED ON THE VERGE OF FUEL STARVATION; AT THE DEST.

Narrative

I WAS ASKED TO FLY ANOTHER PERSON'S AIRPLANE ON A FLT BTWN 2 UNCTLED GA ARPTS; ABOUT 45 MINS APART; UNDER DAY VFR CONDITIONS. I CHKED WITH FSS AND RECEIVED A WX RPT; MEASURED THE ROUND-TRIP DISTANCE ON A CURRENT SECTIONAL CHART; COMPUTED FLT TIME; AND USED THE MANUFACTURER'S POH TO CALCULATE FUEL NEEDED. TO THIS; I ADDED ADDITIONAL FUEL FOR A PART 91 DAY VFR FUEL RESERVE. THE OWNER FUELED THE AIRPLANE; CHKING THE AMOUNT OF FUEL WITH A HOME MADE DIPSTICK; WHICH SHOWED SLIGHTLY MORE FUEL ON BOARD THAN MY FLT PLANNING SHOWED WAS NEEDED. I FILED A VFR FLT PLAN; TOOK OFF; ACTIVATED WITH FSS; AND FLEW THE FIRST SEGMENT WITHOUT TROUBLE (WINDS WERE LIGHT AND VARIABLE AND FLT TIME WAS WITHIN 5 MINS OF THAT PLANNED). ON THE RETURN FLT; JUST BEFORE ENTERING THE TFC PATTERN; THE ENG BEGAN RUNNING ROUGH. I THOUGHT IT WAS CARB ICE; AND APPLIED CARB HEAT; WITHOUT EFFECT. (ONE FUEL TANK SHOWED ALMOST EMPTY; THE OTHER MORE THAN 1/2 FULL.) I ADVISED ATC OF A POSSIBLE CARB ICE PROB; AND LANDED ON THE RWY AT THE DEST ARPT WITHOUT DAMAGE; AND WITHOUT NEEDING EMER SVCS. I CONDUCTED A POSTFLT AND WAS SURPRISED TO FIND THE FUEL TANKS ALMOST EMPTY; AND BELIEVE THAT THE PROB WAS PENDING FUEL EXHAUSTION RATHER THAN CARB ICE. (THE OWNER LATER TOLD ME THAT THE ENG WAS SEVERAL HUNDRED HRS OVER TBO; HAD A FUEL BURN MUCH HIGHER THAN THE POH SAID; AND THAT THE FUEL GAUGES DIDN'T WORK RIGHT.) FROM THIS; I HAVE LEARNED A LESSON ABOUT FLYING XCOUNTRY IN OTHER PEOPLE'S ELDERLY AIRPLANES THAT BURN MORE GAS THAN THE PUBLISHED FIGURES!