I picked up a double axle U-Haul trailer and helped my buddy tow his new 1987 pontiac firebird. I was pretty impressed with the gas mileage pulling all that weight. I was averaging 13 on the highway doing 50-55. Good power too despite all the weight, no downshifting uphill even at like 1500 rpm. that hemi is a good engine.

 

That's really good. I towed a full size fully loaded snowmobile trailer (around 7k-7500lbs I would estimate) and got 9 mpg between interstate-75 mph and highway-65 mph

 

Yes that is good. Today I pulled a double axle, 6 x 12 covered trailer with a living room set and a bedroom set in it, as well as my entire bed filled and I got 11 mpg going 75 mph. I like that....