MPG Motor Magnum vs. Hemi

I see no reason why a 5.2 should not get really decent mileage. "Back in the day" a friend had a 318 2bbl Charger (68?9?) that routinely pulled down 19 or so

I swapped a bone stock 71 340 into my 70 RR "back then" and later added headers. Even with my "uncareful" driving it would get 17.5.

These RAM pickups are HEAVY. Even my "White Whale I" the 97 1500 2wd was near 5K or so I never drove it "highway" enough to get any sort of baseline, it was high mileage and I used it mostly to tow.