I own a 2003 f150 4X4 5.4l super crew truck and I was thinking about putting some money into it to improve power and fuel efficiency. I was particularly looking to get an exhaust system put on it but I have heard that might decrease my fuel economy if I eliminate too much back pressure. Does anyone have any suggestions, I would appreciate them.

 

What kind of exhaust system are you thinking about?
If your just doing a cat back, that will have no effect on the back pressure. Wont do much for power ether...lol
Electric fans help a little.