Hello, I'm new to the forum and also to the diesels. I just bought a 04 duramax crew cab, I'm not sure yet if it is a 2004.5 or not, what is the difference? also the truck has the edge juice with attitude. I'm wondering what I should be getting for fuel milage, we recently took a trip and pulled a 17' boat loaded with gear and I only was getting 13 mpg is this good? I thought it should be better than that, but I don't know. Also with the edge pulling the boat should I alway's have it set on tow or milage? -

Thanks

Check the 8th letter of the vin, if it is a 1, you have an lb7, if it is a 2 you have an lly.