i am getting 12 mpg after plugs wires fuel filter what next?

Hi 2bobs! According to the Federal Trade Commission, here's a few maintenance tips to help your fuel mileage. Hope these help. Good luck! * Keep your engine tuned. Tuning your engine according to your owner’s manual can increase gas mileage by an average of four percent. Increases vary depending on a car’s condition. * Keep your tires properly inflated and aligned. It can increase gas mileage up to three percent. * Change your oil. According to the U.S. Department of Energy (DOE) and Environmental Protection Agency (EPA), you can improve your gas mileage by using the manufacturer’s recommended grade of motor oil. Motor oil that says “Energy Conserving” on the performance symbol of the American Petroleum Institute contains friction-reducing additives that can improve fuel economy. * Check and replace air filters regularly. Replacing clogged filters can increase gas mileage up to ten percent.