If you want to get better gas mileage keep your stock intake. The colder the air the flows over the IAT the more fuel will be used. My MPG dropped 2-3 when I installed my own true ram air intake. Thankfully I have some Michelin tires on there that increased my mpg by 2-3, so it balanced out
Thats another good thing: Type of tire. Yes air pressure is important but tire pressue along with the right tire can increase your mpg a significant amount