My Sub is basically bone stock. The FSD is remote, and it runs straight exhaust - no cat or muffler. For work I put about 1200 highway miles a week on it. With 3.73's I am able to get as high as 19.5 mpg. Other than some wear items, no real issues. What amazes me still is that with all the miles, it will fire right up, unplugged, at -20* (some places just don't have an outlet). And, because it is a sub, I can load the whole family (five of us plus a dog) in, with our camping gear and head out for the weekend. It is a good truck.