It sounds like you aren't going into Lockup , Does your RPMs Kinda Match with the Speed .
When You get to hyway speed there should be an RPM drop after the Last gear shifted .
I have a 2011 W/ the 1.4 turbo and I wasn't getting as good miliage until I gapped the Plugs to .035
You have a different engine check the gap and open it to .030 and see what happens there .
You should get one of you Techs to scan the vehicle and see what its doing with Data Stream.