A low-emissions diesel fuel comprises a catalyzed blend of fatty acid esters, preferably derived from soybean oil and/or tallow and aviation kerosene. The catalyzed blend is effective in lowering regulated emission pollutants, among which are NO.sub.x, particulates, hydrocarbons and carbon monoxide. The catalyst will comprise fuel-soluble platinum and/or cerium or iron. The cerium or iron are typically employed at concentrations of from 2 to 25 ppm and the platinum from 0.05 to 2 ppm, with preferred levels of cerium or iron being from 5 to 10 ppm, e.g., 7.5 ppm, and the platinum being employed at a level of from 0.1 to 0.5 ppm, e.g., 0.15 ppm. A preferred ratio of cerium and/or iron to platinum is from 75:1 to 10:1. The jet fuel component will typically be employed at a volume ratio to the fatty acid esters of from about 2:1 to about 5:1, e.g., about 4:1. The full range of blends extends from 50:1 to 1:50 with some benefit. The jet fuel component of the blend preferably contains grade 55, 50-300 ppm detergent, 25 to about 500 ppm lubricity additive and 0.1-1 ppm platinum COD and 5-20 ppm cerium oleate or octoate. In addition to the fuel blend, a method is provided for reducing the emissions of pollutants from a diesel engine, comprising running the engine on a fuel as defined.