Well, the ol' Burban fired up okay and ran pretty good at 3 degrees F and it will be below zero in the morning. I usually don't touch the accelerator unless it doesn't catch within a few seconds, then I slowly push it down until about half way if it's really cold. Smokes a lot for about 15 seconds then clears up and smooths out. I'm not using any additives at all and haven't had any problems yet. When should I worry about my fuel gelling? Anybody have any stories to tell about REALLY cold weather driving with a Chevy diesel?