Originally Posted by
sarujo
Yes to the air filter, less weight, keeping car maintained, synthetic fluids etc but how you drive is key. Coast and hypermile when you can - look ahead and plan the lights. Constant stops and starts drink more fuel and especially idling. Plan routes and avoid short trips, especially in the winter - engine is most efficient when at operating temps. Driving slower on the highway is also a good way as well - ie 95 to 100
If you really want to be anal...make sure none of your brakes are dragging and keep alignment within spec. And finally, choice of tires will affect mileage as well..