Abstract: This invention relates to a process of dewaxing a hydrocarbon oil involving the steps of separating and precipitating the wax component of the hydrocarbon oil. This process is facilitated by incorporating into the oil a linear polymer of carbon monoxide with one or more olefins comprising .alpha.-olefins with at least 10 carbon atoms per molecule (C.sub.10+ .alpha.-olefins) wherein in this polymer monomer units of carbon monoxide and olefins are present in a substantially alternating arrangement. Optionally, the process may also involve the use of a polymer of one or more olefinically unsaturated compound comprising of alkyl acrylates or alkyl methacrylates with at least 8 carbon atoms in the alkyl group (C.sub.8+ alkyl esters). The process may be practiced using the single-stage or multi-stage dilution method.