A B757-200 WAS DISPATCHED AFTER DEFERRING THE #2 GENERATOR PER THE MEL. APU OIL SVCED AND #1 GENERATOR DRIVE SVCED PER MEL. APU SHUT DOWN INFLT DUE TO LOW OIL WARNING.

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MAY/XA/06; I WAS ASSIGNED TO WORK A FLT. THE ACFT DEPARTED THE GATE AND ON TKOF ROLL IT LOST ELECTRIC OUTPUT FROM THE #2 (R-HAND) IDG (INTEGRATED DRIVE GENERATOR) SYS AND RETURNED TO THE GATE. I WAS ONE OF 2 MECHS ASSIGNED TO MEET THE RETURNING ACFT. WE DECIDED TO MEL THE R (#2) IDG SYS AND PROCEEDED TO COMPLY WITH THE MEL REQUIREMENTS. THE MEL STATES THAT A REVIEW OF THE OPERATIONAL HISTORY OF THE REMAINING ENG GENERATOR MUST BE ACCOMPLISHED; AND TO SVC THE GOOD IDG WITH OIL AND TO SVC THE APU. AFTER WE ACCOMPLISHED THE SVCING WE COMPLETED THE REMAINING ELECTRICAL SYS CHKS; SIGNED FOR THE WORK ACCOMPLISHED AND THE ACFT ONCE AGAIN DEPARTED. ENRTE TO ITS DEST; THE CREW APPARENTLY GOT AN APU LOW OIL EICAS MESSAGE AND DIVERTED. I BELIEVE THAT ADDITIONAL REQUIREMENTS SHOULD BE ADDED TO THE MEL THAT WOULD INCLUDE A REVIEW OF THE OPERATIONAL HISTORY OF THE APU; INCLUDING OIL CONSUMPTION RATES AND GENERATOR SYS; WITH CONCURRENCE FROM MAINT CTL BEFORE DISPATCHING AN ACFT WITH AN ENG GENERATOR SYS INOP. I BELIEVE THE REASON THAT THE APU GOT THE MESSAGE BECAUSE THE COMPANY HAS INSTITUTED A POLICY OF RESTRICTING APU USAGE IN AN EFFORT TO CONSERVE FUEL. SUBSEQUENTLY THE APU ON THIS FLT MAY HAVE BEEN TREADING UPWARD IN OIL CONSUMPTION BUT IT WOULD HAVE BEEN DIFFICULT TO ASSESS THE TREND SINCE APU'S ARE NOT USED FOR ANY LONG PERIODS OF TIME. ON THIS FLT; HOWEVER; THE APU REMAINED ON FOR AN EXTENDED PERIOD OF TIME; SO ANY OIL CONSUMPTION PROB WOULD BE AMPLIFIED AT THAT TIME.