Originally Posted by FinnMc
I have a 97 F250 Crew Cab(7.5L Gas/Auto) with 73k on it. I have only had the truck a few weeks. Get about 9 in town, Put in a K&N Air Filter, got 13 mpg in a mix of surface streets and freeway. We shall see if this filter is really doing the trick.
Unless the old air filter was completely caked over to the point of seriously restricting air flow, there's no way the K&N would make that kind of difference. Must be driving style changes or yet some other changes you've done.