The purpose of this study was to examine the tribofilm formation and the associated degrees of wear that occur in the boundary and mixed lubrication regimes for environmentally friendly synthetic lubricants and their conventional counterparts. Wear was studied using an SRV4 rotational tribometer to simulate the FZG scuffing wear test (ASTM D5182) giving wear, friction, and load coefficients. To simulate gear wear, a semispherical upper specimen and a lower disc, both made of 20MnCr5 case hardened steel, were used, as they represent the same contact geometry as meshing gear teeth. The FZG scuffing wear test simulation was run with a maximum Hertzian contact pressure of 2600 N/mm², speeds of 50 Hz, and temperatures of 50°C, 90°C, and 150°C. A conventional anti-wear/extreme-pressure additive package composed of phosphorus and sulfur was examined, as well as NEAT fluid. The wear surfaces were analyzed through the use of an optical three-dimensional profiler. This showed the effect of the surface film regime on the wear and friction properties of environmentally friendly biodegradable synthetic lubricants versus conventional lubricants.