I've got a 17 with close to 100k on it. Never added any additives, just fuel. My exhaust brake is always on and I use T/H when I pull the trailer. I had a 6icko too, and like someone else said, it was a temperamental piece of junk. I order all my filters on Amazon and change them at about 10k. Maybe because of the Ford, but I only use Mopar filters. I also ordered a fuel cap from there since I have a flatbed on it now and didn't want the neck open. Towing 10k, I get about 9-10mpg's and unloaded, I average around 18.5.
