A PVT PLT FLYING A C172 FROM ONP TO PAO INADVERTENTLY EXHAUSTED A WING FUEL TANK AND ELECTED TO MAKE A PRECAUTIONARY LNDG AT OAK AFTER SELECTING THE OPPOSITE WING FUEL TANK AND RESTARTING THE ENG.

Narrative

I WAS FLYING FROM ONP TO PAO WHEN I DECIDED TO STOP AT OAK FOR FUEL. WHILE OVER SAU; THE R FUEL TANK SEEMED TO RUN DRY. I SWITCHED TO THE L TANK AND HEADED FOR OAK DIRECT. FUEL ESTIMATIONS HAD BEEN BASED ON THE PREVIOUS LOGGED FLYING CHARACTERISTICS OF THIS ACFT; SHOWING ACTUAL AVERAGE FUEL CONSUMPTION TO BE LESS THAN 8 GPH. BASED ON THESE CALCULATIONS; THE MAX ENDURANCE OF THE ACFT SHOULD HAVE BEEN 6 HRS 15 MINS; OR 5 HRS 30 MINS WITH A 45 MIN RESERVE. UPON APCH TO OAK; MY FLT TIME WAS 5 HRS 15 MINS. DESPITE THESE CALCULATIONS; THE L TANK SEEMED TO RUN DRY WITHIN APPROX 2 MI OF RWY 15. I SET UP FOR MAX GLIDE AND SEARCHED FOR A DESERTED ROAD WHILE HDG FOR ARPT. I ANNOUNCED 'MAYDAY XX' AND SAID I THOUGHT I WAS OUT OF GAS. I THEN SWITCHED THE FUEL TANKS AGAIN AND PUMPED THE THROTTLE. THE ENG BEGAN RUNNING AGAIN AND CONTINUED THROUGH LNDG AND TAXI TO FUEL ISLAND. THIS WAS A LONG FLT AND THOUGH I CONSIDERED STOPPING FOR FUEL AT STS; I WANTED TO GET HOME. GET HOMEITIS WAS A FACTOR; AS WAS THE ASSUMPTION THAT THE ACFT WOULD ALWAYS PERFORM AT LESS THAN 8 GPH. THE FUEL INDICATORS BOTH WORK; BUT DUE TO THE AGE OF THE ACFT; THEIR ACCURACY IS QUESTIONABLE TO ME. MY FUEL MGMNT PRACTICE IS TO ALTERNATE TANKS EVERY 30 MINS AND I USE A TIMER TO REMIND ME. NONE OF THE TANK SWITCHES WERE MISSED AS I RECORD EACH ONE ON MY KNEE BOARD.