I have always gotten 16mpg, but @ 75k it dropped to 9MPG!! The kicker is that there is absolutely NO performance change in the vehicle. ANYONE got experience with or a fix for this? I have changed the belts, hoses, plugs, O2 sensors, new cold air intake, and helix throttle spacer. I run synthetic oil and correct tire pressure. HELP! ANYONE, PLEASE!

 

Have you ever had your injectors professionally cleaned? After I had mine done, my R/T went from 10 mpg back to its nominal 12 mpg.