Won't the computer eventually adjust - re-learn the new settings?
If not, I got a tuner from 5 star. Loaded the 87 Performance tune. After I got done playing around, my mileage increased 1 to 1.5 mpg.
Was going to load the others (87 economy and 87 tow/haul) but decided that the perf tune rocks and left it alone.
I get to pop around and have fun when I want to but still get great mpgs when I need it.
Wait a while and see if the computer re-learns it. If not, and you can afford it, try the tune. I love mine but it can be pricey.
2014 FX4 SCREW 5.0L Black Metalic:Mods: WheelSkins Leather Steering Wheel Cover, Line-X,BakFlip FiberMax, WeatherTech Mud Flaps, Digital Floor Mats & Window vent visors, Red FX emblem inserts with dark gray plastidip on chrome, 4" BDS lift, OEM FX wheels with Grappler 305/55-20's.