Make sure the valves are adjusted properly. Also make sure the battery and starter are 100%. A little power service in your fuel will help and keep it from gelling. Make sure your injectors are 100% and your timing chain is not stretched to much, synthetic oil also helps.
So far I have started mine at 26 degrees without a block heater and she fired right up I didn't even let it glow any longer than normal. A diesel in good shape should have no problem in the winter. (within reason, for our far north and Alaska members
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