A thorough bibliographic survey was carried out to collect literature-available information about blending octane numbers (BONs) of most widely used ethers by the refining industry (mainly MTBE and ETBE). The intention was to review the publicly reported BONs values, to suggest the most appropriate figures for future reference, while also understanding the causes of the differences.Summary tables feature all BON values, either explicitly reported in literature or calculated based on experimental results.Due to synergistic intermolecular interactions with hydrocarbons, BONs typically depend on base stock composition.The octane gain tends to grow as the paraffin content in the base stock increases. Moreover BONs tend to decrease as the octane numbers (ON) of the base stock increase.From a refining industry practical utilization viewpoint, the relevant BONs to be considered should logically be those referring to a typical on-spec gasoline composition (relevant “cluster”), while atypical base stock formulations add a wider scientific dimension.The average values presented in this review have been obtained by normalizing the cluster sub-set of literature-featured blending Octane Numbers of the four ethers. Such figures should be considered as the most reliable “typical” BONs value, to be used as general reference when comparing different octane enhancers alternatives. The suggested most appropriate values are 116.5 BRON and 102.1 BMON for MTBE, 118.8 BRON and 103.3 BMON for ETBE, 110.0 BRON and 99.1 BMON for TAME.