just like to share my winter brew recipe. no freeze-ups yet, even in -10 F. so here it is.
1. brew up some bio w/ koh, however I use about 30% meth. make sure it passes 3/27.

2. DO NOT WASH - just settle for 3 days so the soap drops out w/ the glycerine.

3. blend finished bio with 25% RUG and away you go.

Summary:
The extra methanol added to the process and by not washing the fuel creates a lower gel point product. this alone works to about 20F. The 25% RUG really makes it a good winer fuel. sounds crazy in a diesel, but it has worked for myself and 2 of my freinds. we have been using this mixture for 3 winters now and no problems. that is why I'm finally posting my mixture. Happy brewing