Yes, with a fuel system as large as it is, on these trucks, there's always a certain "Acceptable' amount of water, in the fuel. I was simply inquiring about Cetane, for educational purposes though. I use different additives in my diesel, to reduce water, as much as humanly possible, and occasionally open the bottom plug on my fuel tanks with a full tank. I just let it drain, until fuel comes out, and plug it up. The water sinks to the bottom, so this is very easy, and not an environmental threat, in most cases. You can see when the fuel is coming, and plug it up easily. I do this about twice a season. I also run a water seperator filter, in the trucks. They come with it from the factory, and the filter mount, has a petcock on the bottom also.