2014 Silverado 1500 double cab, 4x4. Six speed auto, 3:73 gears. Averages around 20-22 MPG highway at 70 MPH. Third 5.3L GM 4x4 I've had since 2006. The only one that did worse on gas, was the 2010 w/3:05 gears and a four speed automatic. The 2014 is the best of the bunch.
When it was brand new and the bed wasn't piled half full of jacks, tools, heavy chains, etc. it hit a "best" of 24.3 MPG on the fuel mileage 'puter display back then. That was for about a 500 mile trip, including local driving at the destination and maybe 300+ miles of highway driving. Lost that display last year, when it was in for repairs to an air direction shutter behind the dash and they apparently disconnected the battery?
Best I've been able to rack up since, is 22.4..Truck averages 14 to 15 around town normally, goes down in the winter. Does not like really cold weather for fuel mileage. Creepin' up on 60,000 miles now, no complaints. Truck is also pretty damn quick from a dead stop.
