Abstract: A novel process is disclosed for preparing hydrocarbon mixtures from methanol or trimethyl phosphate. The process comprises heating the methanol or trimethyl phosphate with phosphorus pentoxide, polyphosphoric acid or a species of polyphosphoric acid intermediate between the two reagents at a temperature of circa. 185.degree. C. to 300.degree. C. The hydrocarbon mixtures obtained are useful fuel and lubricant compositions.