On the currenrt 14 automatic with stock converter -
I am running a Roush 2.3L TVS and the Roush stops there. JLTCAI, VMP triple pass H.E, VMP 82mm pulley, VMP boost-a-pump, and VMP tuned to 93 octane. Suspension BMR LCA's, relo brackets, UCA (adjustable), adj. panhard, GT drag springs rear only, Lakewood 50/50 rear shocks. One piece aluminum DS from Axle Exchange, MT ET Street R series 305/45/17 DR's. Exhaust is Lethal Performance OR H pipe and GT500 mufflers. I have front Strange adjustable struts and BMR GT500 drag springs (not GT springs) waiting to go on as soon as it warms up out.
Ran the same power adder on my 13 manual shift with cats and not as much suspension work. Exedy mach 500 clutch setup, MGW shifter on that car with Roush springs all around.
Ran 10.82 best on the 14 and ran 11.49 on the 13 manual shifting gently with less attention to the suspension setup.
Both setups averaged 23-25 MPG on trips and they both saw 4 hour trips making this gas mileage on two lane highway driving. On the interstate running steady 70 mph either setup has run 25-26mpg.
To do it again I would go with the 2.3L VMP package from VMP performance. I was not familiar with VMP when I made my choice some years back. Now that I have I will never go elsewhere.
Hope this helps.