THE PLT REPORTED THAT THE ENGINE LOST PWR ABOUT 20 MILES FROM THE ARPT WHERE HE HAD INTENDED TO REFUEL. THE AIRPLANE SUBSEQUENTLY COLLIDED WITH UTILITY WIRES AS HE WAS ATTEMPTING TO LAND ON A HWY. THE PLT ATTRIBUTED THE PWR LOSS TO FUEL EXHAUSTION. POSTCRASH EXAM OF THE AIRPLANE BY A MECH REVEALED ONLY TRACE AMOUNTS OF FUEL REMAINING ON BOARD. THE PLT NOTED THAT HE HAD TOPPED OFF THE FUEL TANKS PRIOR TO DEPARTURE; THIS SHOULD HAVE GIVEN HIM 5.5 TO 6 HRS OF ENDURANCE, BASED ON PREVIOUS FLIGHTS IN THE AIRPLANE. THE ACTUAL ENDURANCE WAS ABOUT 4.8 HRS. EXAM OF THE AIRPLANE POH REVEALED THAT THE AIRPLANE HAD AN EXPECTED ENDURANCE OF ABOUT 4.7 HRS AT 75% PWR AND 5.4 HRS AT 65% PWR, WITH A 45 MIN RESERVE AT 45% PWR, UNDER THE FLT CONDITIONS REPORTED BY THE PLT. THE POH NOTES HOWEVER, THAT THERE ARE INDETERMINATE VARIABLES WHICH CAN ACCOUNT FOR VARIATIONS OF 10% OR MORE IN AIRPLANE RANGE & ENDURANCE. SEVERAL ARPTS WITH FUEL WERE AVAILABLE ALONG THE ROUTE OF FLT.