Randy,

I have been able to increase my average by 2mpg by driving like an old man and using the cruise control excessively. Even as a commuter on Dallas freeways, I set the cruise at 58mph (yes, in 65mph zones) and the gas mileage just goes up and up and up. Though slow acceleration and braking are a big help, lowering your top speed is the biggest. We're driving bricks, remember.