[MetroMPG]

Blocking directly behind the grille will work nearly as well as in front. Some members do just that for aesthetics.

As for that throttle plate, makes sense that a clean intake would perform best in all regards.

I'm a bit surprised that you're only getting 24 mpg while keeping your speeds down to 60-65. I'd think you'd be exceeding highway EPA by ~5-10% at that speed (assuming you're doing 90% highway).