BigRigTech
Diesel junky
I doubt you'll have any gelling issues....Maybe put some ATF in the mix to keep everything mixed....I have 2 of those 300gal cubes too but I can get oil anytime I want so it's easier for me to just bring it home a little at a time as I need it. When I fill up this week I'm going to try about 30% waste oil in each tank seeing as the temp's are finally starting to warm up around here.