1) Check the air pressure in your tires. Cooler temperatures lower tire pressure and that, in turn, lowers fuel efficiency. So check your tires and make sure that they are properly inflated.
2) As the autumn leaves begin to fall, consider raking them up rather than using a "blower". Once raked up, use them as mulch to protect plants throughout the winter or add them to a compost pile.
3) Bring in any houseplants that have spent the summer outdoors. They'll help clean the air.
4) If your home has no sidewall insulation, place heavy furniture like bookshelves, armoires and sofas along exterior walls, and use decorative quilts as wall hangings. This will help block cold air.