[kach22i]

2-door or 4-door?

Post some photos including a side profile and something explaining the front grille.

There is a sticky on grille-blocks, I forget if it's the top or bottom one you should try first.

Driving style has a lot to with mpg.

Front chin spoilers only really improve aerodynamics if they hang no lower than the dangley parts under the car.

I suspect your Honda is not serious offender in that area, but a few belly shots should confirm.

NOTE:
Conveyor belt material is much better than lawn edging, but more expensive too.

In short, most aero in this forum deals with drag, drag forms on the aft part of the car after the highest part of the roof.

Suggestions will follow photos.