Basically just a mpg tune. I'm sure that someone how developed one by now and i'd like to buy it. That's how it works with the Duramax. Someone writes a tune and they sell it. I'm not sure about the Malibus so I dont know what works and doesn't on them. That's why i'd like to just buy one and try it out. I'm planning a long trip next month and would love to have it before then. I already have a V2.