Few realise that chainsaw bar oil relies on tackifiers that increase stringiness, not just thickness. At high chain speed, oil faces extreme centrifugal forces; without extensional strength it flings off before reaching the bar nose and drive links. Tackified base oil forms elastic threads that bridge from groove to chain, carrying heat and sawdust away while keeping a boundary film. In Nordic forests, wet debris and intermittent runs make this cling crucial after cold starts and pauses. These polymers do not significantly raise viscosity; they alter how the oil stretches under shear. This principle is reflected in Bio-Chainsaw Oil ISO VG68.