Blending does work. I use some Regular Unleaded Gas though. I used to use naphtha, acetone, and turpentine. I tried them all. You do not need them. Some things you should know though. Get a paint viscosity cup and check your viscosity. All cups are different. My particular cup runs Regular Unleaded Gas (RUG) at 9 seconds. It runs diesel at 11 seconds and my blended fuel at 13 seconds. Just thin enough at 60 degrees to flow well. Cold pre-filtering is the key. I learned this from beer making. The animal fats will be filtered out of vegetable at 68 degrees, like protein haze will filter from beer at 31 degrees. Lowering the temperature to 63 degrees does a better job. Lowering it below 60 will cause it not to flow since I use gravity. When using gravity you will get 1 pound of pressure every 2.5 feet of height. My barrel is 7.5 feet up so I get 3 pounds to filter with. You need to remember water filters are nominal and can pass up to 30 microns, especially under pressure from a pump. Hydraulic oil filters are usually 10 microns. Some fuel filters built by WIX are less. FASS has a 3-micron, but I do not know who makes it for them.
As for your buddy with the degree, he must have been absent the day when they talked about the history of diesel. Rudolph Diesel made the engine to run on renewable sources from the farm. My wife has a masterís degree with a 4.0. I love her but she cannot set a mousetrap. She too was absent that day.
Do not be shy just blend, and let me know how it works for you. I want to also let you know adding too much RUG to a winter diesel and using it in the summer will cause injection pumps to not produce enough pressure. In the winter keep a bottle of your fuel outside in a clear bottle when you make it. If it is cloudy from the cold overnight, you need more gas or diesel in your blend. I have added auxiliary pumps to the Mercedes and the Kubota to help overcome the thicker viscosity in colder weather but not cloudy fuel.
Change your oil at 3000 or 4000 miles when you run veggie fuel. Some of it ends up in the crankcase bypassing the rings.
My 6-liter Ford has 58000 miles on it and runs fine. My 6.9 IDI runs fine. The Kubota now has a heated fuel filter from WIX that filters to 5 microns.
I have got to know if this is for real. Did you really do this with success so far? I have a friend who has a BA as a diesel mech and decades of experience and he says no, dont do it. Can you tell me more?