First ,10 ply tires are typically for 3/4 ton and up , not for a 1/2 ton pick up , But since you have them you need to run the air pressure called for that tire . That will help .
Programmers for gas and diesels is apples and oranges . Diesels can gain massive HP and or small feul mileage depending on setting . Gas motors gain very little of either . I have both . Rough example = if you get one MPG gain , which you probably won't ,
One tank of fuel every two weeks , it will take two years to break even figuring the programmer cost at 350 . If you want fuel mileage buy a PRIUS
