Dielectric fluids are provided, the dielectric fluids comprising a mixture of polyol esters derived from a reaction of a) a polyol comprising pentaerythritol, trimethylolpropane, neopentyl glycol, or combinations thereof, and b) a mixture of fatty acid esters derived from a high oleic soybean oil comprising fatty acid moieties, wherein the high oleic soybean oil has a C18:1 content of greater than 65% of the fatty acid moieties in the oil, and a combined C18:2 and C18:3 content of less than 20% of the fatty acid moieties in the oil. Also provided are electrical apparatuses comprising the dielectric fluids, and processes for preparing the mixtures of polyol esters.