you have enough miles on it where you could consider aftermarket products. but you mpg sounds better than most. you could look into spartan and innovative diesel. theres a guy on ford-trucks.com selling his badp tuner with dpf delete for 700. his names pahrump, he's also on the diesel garage. intake wont gain much besides setting a check engine light.. my dealer cleared mine but it came back on the same day. but i like the way it sounds and performs. hope this helps