I have a Edge Evo Race and DPF/Cat delete on my 2008 6.4L and about 14K miles on motor. I get 18ish on daily driving, and 23ish on all highway trips. Thats if i dont get into the pedal...lol. Got about 14/17 stock. So, happy with my 18/23 now. But dang, wish i could get 50+ mpg too...lol. Wait, i saw on ebay some dumba$$ was selling a chip for $20 bucks that would add 100HP and 50+mpg. I sent him a message and asked if hed pay the return shipping if i bought it, but no reply. Imagine that...haha.