 Crisp fall mornings turn bitter cold. You climb into your diesel and it feels like you're sitting on an ice cube. Imagine how your engine feels after a frosty night. Freezing temperatures impact your diesel's fluids, especially fuel. As the temperatures drop, water that is emulsified within your fuel is released, adding more water into your system. Frozen water in your fuel lines, filter, or bowl will simply slow the flow, or worse, stop the flow of fuel in your system. No fuel flow, no start.