Yesterday we tackled the reasons why 2 cycle and 4 cycle oils are not interchangeable. Today I will explain how the formulas differ. For starters, 4 cycle oil is specifically manufactured with additives, like viscosity index improvers, to inhibit oil consumption. In other words, the formula makes oil harder to burn.
On the other hand, 2 stroke oil is specifically formulated to burn away, leaving minimal residue on spark plugs, cylinders, and exhaust ports. Another aspect of the formula is to inhibit pre-ignition. The formula also protects against rink sticking and crankcase sludge.