I was guilty of not following this tip for awhile, and, when I changed, I really did see a difference.
Today's tip is Don't Pack Heavy Stuff. Many times we load down the trunks of our cars or the beds of our trucks with stuff and drive around. The heavier the stuff, the less miles per gallon we get.
For several months, I had about 5 garbage bags full of old clothes in my trunk. We put them there so we could go through them piece by piece without having garbage bags in the house. When we finally did go through them and I got rid of the bags, my gas mileage improved noticeably.
The weight issue also comes in to play in the Winter. While they may remind you of cold weather, knock off those icicles. They will kill your gas mileage!