One of the main problems I have found is cold temps.
After you get the fuel it will work fine. There is a a list online of what % of premixed fuel you can use with store bought fuel mixxed together depending on the oat side air temp. When it starts to get cold your fuel/mix will start to gel and won't pump through the lines. You can also go online and buy complete kits, making it really easy and cheap to make fuel. Last I checked it was about .63 cents a gallon. Kits depend on how much you want to make and how much you want to be involved. The more you are willing to do the cheaper it is. But we makes more mistakes than the equipment. I was looking for one that would make about 1000 gallons a day,
I was running 5- 2005 diesel trucks. Then you get into the whole idea of running heaters in your fuel tanks. another discussion point.
Mark
Here is one of the equipment manufactures web address Biodiesel Kits - Biodiesel Processors - Making Biodiesel and if you google making bio diesel you will come up with a huge amount of sites. I can't stress enough how important it is to read the instructions. That is where it discusses temps and so on.. Not much worse than getting half way accross the country and your entire tank of fuel turn to gel!!!!!
Mark