This will stir the pot for sure. Just my own personal experience with the small block Mopar. I had a 1989 D-150 318 a/t and 2.73's 2 wheel drive and it's best was 14-16 on the highway. My 1998 wasn'tmuch better.Even my dad's 1998 D-150 only got 18 on the highway. My parents 1985 5t Avenue got 28 on the highway, but that was probably due to the fact that had the lean burn system on it. I've never known anyone who got good mileage from a 318, I'm not saying that it hasn't happened or that it's impossible. But I will say that I've heard more people say that mopars are not known for mileage and for my experience it's true