leave em in. Mileage is mileage. I haul wood and get groceries with mine. It is a truck and gets treated/used as such. You can't save money/increase mileage by leaving bad numbers out. I USE my truck and I use my real mpg numbers. I usually average 20-25 mpg. I have now removed A/C, P/S, SMOG, and shortened the belt. We shall see what happens. So far, so good.
Good luck