[LaMarr]

I only have a few million miles under my belt.

Fleet Frieghtliner FD's I was the highest mileage of the fleet. 7.9 but the engine was always off when I wasn't driving. Top speed 62 mph.

1996 Volvo with side, roof and bumper fairings Never below 7.5 mpg per tank.

2001 Volvo VN, 6.9 mpg average for life of truck. The front fenders tried to lift air over the wheel instead of to the side of the truck. The front bumper was higher from the ground. The windshield was wider and there wasn't as much curvature on the sides.
The mirror housings were curved but they pushed a bigger hole through the air than the stock mirrors on the older truck. Again I never idle to sleep. But as with the 96 volvo I did drive the speed limit 75 mph.

An interesting note. the 86 K100E cab over got better mileage than the 2001 VN.

Yes I do believe in streamlining and especially Bernoulli's law of fluid dynamics.

I also pulled a trailer for a couple trips with the side fairings but when docks were in a hole it would bottom out so I was unable to get to some docks to load.

LaMarr