When purchasing a chip for a diesel truck you want to make sure it has some of these features; Easy snap in installation, and you want the chip to be able to be easily removed for servicing. Also, One think you need to make sure you get is a chip that doesn't void your warranty. The rest of the features are pretty much depending on what you want in a chip such as how much speed boost you are wanting as well as how much more fuel efficiancy you are wanting.