Lower grille block ABA test on Skoda Fabia
 

Some ABA testing on a lower grille block - confusing results I think but that probably shows how tricky it is to get good results from this kind of testing in real-world conditions.

Imperial MPG data from on-board computer
A: no lower block
Northbound, Southbound
78.9, 81.4
80.5, 81.5

B: lower block (duct tape)
North, South
86, 79.4
85.1, 79.1
85.6, 74.7

A:
North, South
79.7, 87 (traffic)
82.4, 73.2 (lights on)

Averages:
A: 80.6
B: 81.7
A: 80.6

Result: +1.4%

However, taking just the "northbound" data then the averages are
A: 79.7
B: 85.6
A: 81.1
Result: +6.5%

which show a much larger improvement- but thats cheating.

Cool test. I'd take a +1.4% increase anyday! Got any pics so we can see what grill shape was and how it was modified?

I just have my grill blocked with styrofoam right now, but looking into other options.

The lower grille can be seen under the numberplate in this pic:
Skoda Fabia in India mid 2005 - photos, pictures, gallery