What is the deal with programmers? I'm not very much of a car guy, but have heard some guys talking about programmers and chips in their trucks to get more power and better mpg. I have a 2007 chevy 2500 duramax - the last model and engine before they went ultra low sulfur. I put about 12-15k on it each year. 85% is around town pulling a double axle trailer with 1-2 mowers and all the extras. I'm only getting 10.7 mpg. I would like to get something to make the mpg go up and save a little, but don't want to mess up the computer or add to the serviceing of the truck. If anyone has a make and model of a programmer that they like and would recommend I would like to know. Also where did you get it.