Fuel economy at 65 mph vs 60 mph

johndeerefarmer wrote:
What fuel economy increase have you observed from pulling your fiver at 60 mph vs 65 mph?

My personal experience is about 1.5 mpg increase by dropping to 60 from 65. See the rig in my sig. I've simply not towed far enough at any given time to see if I have a "sweet spot" somewhere in between, as many people say. A lot of D'max owners seem to do well at about 62 mph, for some reason. That being said, the best mileage I've ever seen in my truck, not towing, was on a trip to CO 3 years ago, with an empty 14 cu ft chest freezer up against the back of my cab and driving 75 mph the whole way. Got right at 23 mpg and it =still= has me scratching my head on how it changed the aero profile. :-)

Lyle