An enhanced diluent (EDIL) composition used to prepare a transportable dense crude oil composition is disclosed. An EDIL composition contains a usually used dense crude hydrocarbon diluent (DIL) plus an additive (ADD) composition that permits the amount of EDIL used in the resulting diluted transportable dense crude (EDIL:DC) to be lessened by about 20 to about 60 percent, while maintaining the viscosity and other properties of the usually used DC:DIL composition. A contemplated ADD composition is a mixture of three components, a solvent mixture, a diol and a surfactant. A contemplated EDIL composition contains about 1 to about 20 percent by weight of the ADD composition. Admixture of EDIL with a dense crude at about 80 to about 40 percent by volume of the amount of DIL usually used provides an easily transportable enhanced dense crude composition. A method of preparing a transportable dense crude composition is also disclosed.