Abstract: Methods, biological oils, biofuels, units, and/or organisms directed to use in compression engines. A method of producing biological oils includes producing an organism and having the organism consume a feedstock. The organism includes a lipid containing fatty acids. The organism meets or exceeds at least two metrics. The metrics include: A) a cell density of at least about 115 grams per liter; B) a fatty acid content of at least about 49 percent on a dry mass basis; C) a fatty acid productivity of at least about 15 grams per liter per day; D) a fatty acid yield of at least about 0.175 grams of fatty acids produced per grams of the feedstock consumed; E) a 24 hour peak fatty acid productivity of at least about 30 grams per liter per day; F) an extraction efficiency on a percent of total fatty acid content basis of at least about 50 percent; and/or G) yield of fatty acids on oxygen of more than about 0.4 as grams of fatty acids produced per gram of oxygen consumed basis.