https://www.fueleconomy.gov/feg/bymodel/1985_Dodge_Charger.shtml

has the fuel economy ratings. I got about 17-19 with my 85 Charger, but I was in highschool and really didn't treat it that well. the economy got worse when we swapped the 2.2 turbo out of my mom's wrecked shadow into it but the fun factor went up a fair bit.