Specifically sperm whale oil, in sulfurized form, was the main EP additive used in gear oils until the late 70's, until it got banned (worldwide) as raw material coming from endangered species. At that time the price had already climbed sky-high (about USD6000/ton) so it was just logic that the industry switched to cheaper (and often better) substitutes.
Whale oil has a very unique (chemical)composition and unlike vegetable oils, or i.e. common fish oil, it is a "non-drying" oil: no gumming-up of parts or the typical tackiness from being exposed to air. Also when cold-filtered it would stay liquid and clear for days, at 0ºC.
Sure enough it burns very nice and it would be an excellent fuel alternative for our MF-powered toys, BUT... as it was mentionned above: it IS a BAD WORD!
Don't even think about telling anyone about putting it in your tank, even if you could get it for free...!
G.