Originally Posted by mrdeath2000
You can remove the flaps and have your car tuned to run without them. I had that done in my 06 Mustang GT (see CMDP plates, charge motion delete plates)
The 2.0 has the tumble flaps and there was a change between 06 to 07 in the factory tune of them that actually bumped up the mpg in 07.
I 2nd that ^^^^. Runs better w/o them. For the Mustangs you can buy oem charge motion plates w/o the flaps or you can get alloy plates, then you'd need a tune.