Grille Block Failure

[Snax]

So I spent an hour making an ABS grille block for our 5. I designed it as a partial block which eliminates about 2/3 of the lower grille flow area since I didn't feel that the upper grille opening is likely sufficient in all but the coldest weather for cooling. With a triangular shape, point down, it also permits unrestricted airflow to the intake and fender cowls. But as you can assume from the title, preliminary test results are disappointing.

My test loop was a relatively short 10 miles, but that was enough to illustrate a lack of significant improvement if not reduced economy and abort more accurate testing. Road speed was 55 MPH on cruise control and 70F.:

Grille Block Test Result: 37.9 MPG
No Grille Block Result: 38.5 MPG

Considering how odd the thing looks, I'll do a cursory complete lower block test, but likely move on to other options.

P.S. I have not run a full tank through since installing the Scanguage, so the mileage figures above are uncalibrated and probably on the optimistic side.