Auto Talk 101: Tips on Improving Your Car's Gas Mileage - as part of the expert series by GeoBeats. To give the best fuel economy from your car, there are a number of things to consider. One might be tire pressure, and your tires should be inflated to the proper pressure in order to get best fuel mileage, in order to keep the car rolling at its maximum. Another thing to consider is the fuel system. Are you using the proper gasoline? Are you using the proper fuel octane? And do you occasionally use a fuel system additive to keep that fuel system running clean? Filters would be another consideration. Your fuel filter should be replaced approximately every 30000 miles on every car, and that will keep that system running a little more smoothly. Another thing to consider is your primary and your secondary ignition systems, just talk basically about your spark plugs and ignition wires, they should be current and in a good repair. That will give you the best fuel economy from that system.