Welcome to the greasy drivers club.
I have 3 MB300ds on a 50% WVO:Biodiesel blend with no problems in mid winter in West Oz (Temperatures regularly hit 5 degrees overnight - Oh yeah that's 5'C, not F )
One of these (the '84) is now running a second tank on straight WVO, with a heat exchanger in the engine bay and a separate fuel filter.

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Tony from West Oz.
Fatmobile 3 84 300D 295kkm Silver grey/Blue int. 2 tank WVO - Recipient of TurboDesel engine.
Josephine '82 300D 390kkm White/Palamino int.
Elizabeth '81 280E, sporting a '79 300D engine.
Lucille '87 W124 300D non-turbo 6 cylinder OM603, Pearl Grey with light grey interior


Various parts cars including 280E, 230C & 300D in various states of disassembly.