Even though you said no full sized v8's. I'd look at them and try to convince mom. I've had 2 Dakota's now and neither of them got very good mileage. My 98 Silverado got better mileage with my, then 18 yr old lead foot, about 17-18 mpg unloaded and 14-15 loaded (then 2000-2500 lbs typical trailer weight). My 04 Dakota (4.7 v8, 4.11 rear, 5 spd auto) gets around 15 on a good day, 10-12 pulling any real load (2500-3000 lbs total) and 7 up steep grades. It pulls really well, but doesn't get good gas mileage at all.