What is the purpose of them. From what i have read you get more performance when you remove them. Are they for MPG's? I am debating wether or not to get them and I can decide if it's a wise buy. I have a K&N cold air intake and a SCT X3 tuner on a 2008 5-speed GT . Would i be better off with the delete plates or under drive pulleys?

 

Welp! I guess know one knows so I found the answer myself. Now I will share it with you. "At the end of each intake runner was a new-to-Mustang feature Ford called a charge motion control valve. At low engine speeds and light loads, these specially shaped control flaps closed to speed the intake charge and induce a tumble effect in the combustion chamber. That caused the fuel to mix more thoroughly and burn more quickly and efficiently. At higher engine speeds, the charge motion control valves opened fully for maximum flow into the combustion chambers."

 

Interesting,I think Im going for them,theyre sopost to give 10hp wich sounds good when ur at 390