[richl]

what state do you live in ??????? are they still using oxygenated fuel???( winter blend) if so that alone will cause any vehicle to drop in mileage .......

wait till mid early summer again . and check your mileage i bet it will go up .

winter blends on fuel burn way easier ( gm has a ton of service bulletins on this) . and you mileage will suffer about 10-25% .. i hear this complaint every late fall to early spring ..... mine drops off about late October and don't pick up till the end of march mid April ..on that fuel alone.. but i am a master Ase tech as well as a gm master tech . i don't know a thing .........

at lease that what the wife keeps telling me .............

and don't waste your mula on 93 octane. the computer was not calibrated to run on that exclusive. well cross that bridge when we come to that ....