Grill Block 2.25% Increase @ 50 mph.
 

After the air dam failing to gain mileage, I decided to go another route while I ponder the air dam some more.

I went to Home Depot, bought some 7$ flashing and then made a cardboard template. Using the license plate bracket and some leftover aluminum angle, I fabbed up some quick mounting brackets. I also put some angle inside the bottom grill opening to hold the bottom of the flashing in. Once the cardboard template fit, I traced it onto the flashing. I then used some self tapping screws to hold the flashing to the brackets.

Here is the pic I took.
http://i251.photobucket.com/albums/g...ps0d06eded.jpg

Coolant temp stayed right at 195-200*, which is normal. I'll be sure to watch it as the weather gets warmer.

After ABA testing tonight at 50 mph, I got an increase of 1.7% one way and 2.8% increase the other way. Average gain was 2.2%. That is about 1 mpg at 40 mpg. Hopefully the net gain will be higher the faster the car goes. I am out of time to test until next weekend though.

It will take a few miles (4,000) to pay off, but I'll take the gain! I am going to paint it black when I get a minute so it doesn't stick out as much.

Nice work. Congrats with the good result.

Dont forget half the upper grill too. Air dams work best with use of grill block. You want to prevent as much air as possible from going through or under the engine bay. If you jsut do an air dam, then most is sucked through the grill do to the vacuum effect it creates. :eek:

I ran out of time for the upper grill. It is on the to-do list.

So, what your saying is I need to throw my air dam back on and go test again?? The dam is already made. It takes 5 minutes and 8 screws to put back on.

Looks a lot like mine . . . .well, you used the same material anyway!
For the 7 dollar roll of flashing, you should also be able to do the fender skirts.

Oh yeah, 10' of flashing will go a long way...

Looks good! Definitely put an upper grill block on when you get a chance. I found that in the summer, I needed a cooling slot maybe 12"x2" is all; I situated it about where the bottom of the license plate is.

If you paint it, your payoff will 4,050 miles! :p

Nice work, hopefully after a tank or two of highway speeds, you'll see a better gain. I wouldn't do the upper until you know what temps. do to engine temp with the current block. Either that or make it super easy to remove (like pull over and be able to unclip it easy).

What made you go with metal flashing material rather than coroplast?

It is cheap and easy to work with. I cut it with EMT shears.