A composition for treating diesel fuel, comprising: dimethyl carbonate; and a multifunctional additive comprising: a phase stabilizer present at 20-99 wt% of the multifunctional additive; and a cetane improver present at 0.5-20 wt% of the multifunctional additive, wherein the cetane improver is selected from the group consisting of iso-amyl nitrate, iso-octyl nitrate, cyclohexyl nitrate, butyl oxalate, dibutyl oxalate, di-iso-pentyl oxalate, di-tert-butyl peroxide, tert-butyl peroxybenzoate and a combination thereof, wherein the phase stabilizer comprises: a methyl ester of low carbon number present at 80-90 wt% of the phase stabilizer and selected from the group consisting of methyl acetate, methyl acrylate and methyl butyrate, and an alkyl alcohol, an aromatic alcohol, a ketone, an ether, or a combination thereof, said ether is selected from the group consisting of methyl tert-butyl ether and di-ethylene glycol dimethyl ether, wherein when the composition is added to a base diesel fuel to form a diesel fuel composition, the base diesel fuel is present at 50-95 wt % of the diesel fuel composition, the dimethyl carbonate is present at 2-50 wt % of the diesel fuel composition, and the multifunctional additive is present at 0.01-10 wt % of the diesel fuel composition. dimethyl carbonate; and a multifunctional additive comprising: a phase stabilizer present at 20-99 wt% of the multifunctional additive; and a cetane improver present at 0.5-20 wt% of the multifunctional additive, a phase stabilizer present at 20-99 wt% of the multifunctional additive; and a cetane improver present at 0.5-20 wt% of the multifunctional additive, wherein the cetane improver is selected from the group consisting of iso-amyl nitrate, iso-octyl nitrate, cyclohexyl nitrate, butyl oxalate, dibutyl oxalate, di-iso-pentyl oxalate, di-tert-butyl peroxide, tert-butyl peroxybenzoate and a combination thereof, wherein the phase stabilizer comprises: a methyl ester of low carbon number present at 80-90 wt% of the phase stabilizer and selected from the group consisting of methyl acetate, methyl acrylate and methyl butyrate, and an alkyl alcohol, an aromatic alcohol, a ketone, an ether, or a combination thereof, said ether is selected from the group consisting of methyl tert-butyl ether and di-ethylene glycol dimethyl ether, wherein when the composition is added to a base diesel fuel to form a diesel fuel composition, the base diesel fuel is present at 50-95 wt % of the diesel fuel composition, the dimethyl carbonate is present at 2-50 wt % of the diesel fuel composition, and the multifunctional additive is present at 0.01-10 wt % of the diesel fuel composition. a methyl ester of low carbon number present at 80-90 wt% of the phase stabilizer and selected from the group consisting of methyl acetate, methyl acrylate and methyl butyrate, and an alkyl alcohol, an aromatic alcohol, a ketone, an ether, or a combination thereof, said ether is selected from the group consisting of methyl tert-butyl ether and di-ethylene glycol dimethyl ether, wherein when the composition is added to a base diesel fuel to form a diesel fuel composition, the base diesel fuel is present at 50-95 wt % of the diesel fuel composition, the dimethyl carbonate is present at 2-50 wt % of the diesel fuel composition, and the multifunctional additive is present at 0.01-10 wt % of the diesel fuel composition.