Have you guy's who installed a cold air system and a dual after CAT exhaust system seen any MPG gain?

I'm installing this this week and I'm hopeing to see a couple of MPG increase, Am I off base. I have the 5.4L KR 4x4.

 

You will see very little gains in MPG to none at all. In fact, you will likely see a drop in MPG because of the new sounds that you will get from the induction/exhaust system that will be due to you maybe getting into the throttle a bit more than usual. You can expect to see more MPG if you use a tuner. Good luck!

 

What type of MPG gains could I expect with a tune?

 

I ran Troyer's 93 Octane Performance, AF1 (3.5") and Roush Off Road SIDO with my 2007 Screw. If you can keep your foot out of it - and I mean ALL THE WAY OUT, you may see 1.5mpg on the highway. I found enough to offset the cost of the high octane while still feeling the performance of the 93 octane. I still gained about the same with the 87 octane tune, but it wsn't as fun. Again, you need a really light foot, and mine is the not the rule... more the exception.