Just wondering what other people are getting. I think I'm getting about 18 mpg but I'm about to do a definitive test where I run a measured amount to see exactly what I get. I just want to know what I'm really getting.

 

As I recall, the 3.9 was advertised with only a little better mpg than the 5.2, which was advertised as a little better than the 5.9, which was advertised as a little better than the 8.0, which was advertised as the most powerful engine in any pickup truck.

If you're getting 18 with the 3.9, while most 5.2s and 5.9s only get 11-13, then I'd be happy and move on. If you want great mileage with a 2nd gen, get a Cummins.