Yeah, we thought nothing of it then...the 4dr got when sold the Charger was a Buick Electra 225 w/ the 455 iirc...
The Charger actually was pretty good on mileage--we bought it to spec and put in a gear ratio to bring rpm down some at highway speed--took away a little of the acceleration performance, of course, but it was still plenty enough. For the time it was a great Interstate road car--not squishy soft suspension but still reasonably quiet. At the time we were in Lynchburg and traveling to far SW KS regularly where both sets of grandparents were--about 1550 mi trip before I81 was finished from Roanoke to Knoxville and I40 ended at Crab Orchard Mtn w of Knoxville across the Cumberlands and then dumped you in downtown Nashville. Another uncompleted stretch thru AR hill country from just west of Little Rock to nearly Ft Smith...
The bummer was the lead plugs that sealed machine holes in the Holley split-barrel carb would get soft after two long days on road and in the morning when cold they leaked. Had to reseat them w/ a small hammer the second morning before heading out again... :)
It also developed some nasty electrical problems w/ time...