Should the rear wheels turn freely?

I had the rear end on jack stands yesterday, and while I was under there I turned the rear wheels by hand to check the tires. For about 3/4 of the rotation, there was a little resistance and I could hear the brake shoes scrape. For the last quarter turn, the wheels turned freely.

Should the brake shoes drag a little bit? Is this why my mileage is only about 20 mpg?

The wheel should turn easily with momentary contact with the brake shoes.The brakes can be adjusted to a constant sound when spinning the wheel easily but no tighter.Everyone adjusts
the brakes to a different level but this has always worked for me.They would have to be almost
smoking to effect the gas mileage though.
JG

The rear brakes have an automatic adjustment system. You should never have to touch them until they need replacement. Every time you back up they will adjust as needed. The drums may not be perfectly round, which could cause the slight difference in freedom of motion. Even a couple of thousandths of an inch can make a noticable difference. The shoes could even be brushing the side of the drum with the metal base of the shoe if the side of the drum is not perfectly flat. The drag would be insignificant in comparison with all the other combined losses in the car.

Thanks for the feedback.