It not me inventing the BTU content of vegetable oil, Sky. That came out of an MIT lab.
If you prefer an non-internet source, check out "The Internal Combustion Engine in Theory and Practice, Volume 2: Combustion, Fuels, Materials, Design" by Charles Fayette Taylor ISBN 0 262 70016 6. On page 170 you'll find "Compression-ignition engines have been run on various kinds of vegetable and animal oils (4.620-4.624). Satisfactory ignition quality, power and efficiency are apparently obtainable with many such fuels, and many of them seem to give little trouble from excessive engine deposits or corrosion."
The reference (4.620-4.624) goes to the bibliography and lists five studies in which the use of vegetable oil was studied in diesel engines. The last one, 4.624, is Loh et al., "Compression-Ignition Engine Performance with Soybean Oil, Cottonseed Oil and Their Blends," Department of Mechanical Engineering, Massachusetts Institute of Technology
That's the thesis I ordered and studied. You'll find the BTU info in that thesis.