Training missions are usually between 3-5 hours and the jets generally fly once a day or every other day.
No wonder. You would never make up the cost of fuel saved vs the cost of the winglets and carying that weight, and maintenance.
I wholeheartedly agree!
A few years back, there was this big focus on fuel savings vis-a-vis weight reduction, and some genius who needed an OPR bullet decreed all the stuff we need when we're TDY, such as cargo straps, chains, and devices, the cargo door sill conveyor, etc. to be removed for all local flights and put back on when the jet went TDY. They even drained the potable water tanks and gave us alcohol wipes to "wash" our hands with (pre-COVID, but they haven't reactivated the tanks). Saved ~ 1,000 pounds per aircraft, which saves ~ 500 pounds of gas per flight and probably saves ~ 50K of gas per year, per tail. Great idea. Only problem is the powers that be have obligated each coast (McGuire and Travis) to have two WARP'd jets per coast at all times, and those jets fly all over the globe, but very rarely do actual WARP AR. Now imagine that WARP'd jet going from CA to Japan, hauling cargo and not doing AR, with an extra 5-6% drag index and burning an extra 15K of gas during the entire mission because they're carrying those stupid pods. So long fuel savings! I know because I've flown a WARP'd jet during cargo runs at least 4 times in the last couple of years, and I'm but one person in one squadron!
At least not flying at optimum altitudes/speeds during training missions makes sense, as those altitudes and speeds are entirely incompatible with air refueling. Simply too high and too fast.