I have an 07 f 150 4x4 got 70k on the truck. I am looking for a little better gas mileage. I've read in several places that adding an exhaust system will help. Also I've read where the cold air intake systems are really not worth what you give for them. Will you guys please help me with my decisions please.

 

I have the Flowmaster Force II single catback system on my truck with a K&N airfilter and can get 17MPG on the highway with stock FX4 wheels and tires. I spent $300 on a CAI and got the same 17MPG. If you went with a dual exhaust it might get better but I dislike the obnoxious sound. Im adding a highflow CAT in the next couple weeks but I doubt that will make much difference.

 

I am probably close to this MPG stock. I've checked it a couple of time round town and getting around 15. On the highway I am about 17. Thanks for the input.

 

I have a 2004 2wd F150 with a 3" leveling kit and 2"AAL. I use to get around 12.5 mpgs in the city. I have dual exhaust, tonneau cover, and I've done the gotts mod. If I'm easy on the peddle I can get around 15 mpg in the city. Haven't checked my highway mpgs yet

 

I have a 2004 Fx4 Scab and I'm averaging 18mpg with my K&N CAI with dual 3" single pipes and a Flowmaster Super 40 on each pipe. Now keep in mind I have brand new spark plugs and ignition coils too.

And unlike some folks, I like my truck loud and obnoxious, haha! Hence the name Thunder! Love it when she rumbles!

 

To the op, I wouldn't expect much if any mpg gains from an exhaust. I would do it for the sound and any additional benefits would be icing on the cake. You will be disappointed if you do exhaust for mpg gains.