I'm thinking about getting a new truck because my Titan only gets me 12mpg. I'm thinking of upgrading to a Diesel and have been for awile. I just don't know if I should go for an '06 or '07 6.0 or go for a new 6.4? I want to get fuel efficiency more than power. Either truck I get I will lift it on 37s possibly 38s, and I still want to get the best mpg's with that setup. So in y'alls opinion, should I go for the 6.0 or the 6.4. Also, I guess I should add, they are offering Employee pricing less $3500 rebate and free gas for 2 years (they didn't say diesel, they said gas so I don't if that applies or not). Let me know your opinions guys. Thanks.