An addition to number 5: Don’t fill your gas tank all the way, and clean out anything in your car you don’t need. Every 100 lbs added to the weight of your car reduces your MPGs by roughly 2%. Having a full tank adds extra weight and makes the gas burn faster when combined with the weight of anything else in the car you don’t need. Also, clean out anything from your trunk that shouldn’t be in there (we’re all guilty of leaving things in the trunk because we’re too lazy to bring it in that day and then we forget about it for weeks). Remove any storage accessories on the outside of the car like bike racks, and if you have a pick up truck, having a bed cover or ladder rack can add unnecessary weight.