I found this video a while back, but was reminded last week just how important fuel treatment and an anti-gel can be. We had temperatures just last week of a -42F windchill here in Montana. This is the best test I've seen, even though it doesn't include every diesel fuel treatment available. The results are surprising... Let us know what your experience has been with diesel fuel treatments...

https://www.youtube.com/watch?v=n8gDN_6esfs