Plastic gears are primarily utilised in manufacturing and automotive industries due to their quiet operation, resistance to corrosion, and lightweight characteristics. Traditionally, injection moulding (IM) has been the preferred method for producing gears. However, the high cost associated with IM has made additive manufacturing (otherwise known as “3D printing”) an increasingly attractive alternative. This study investigated the potential benefits of 3D-printed spur gears made from three distinct types of polylactic acid (PLA) materials: recycled PLA (rPLA), blended PLA, and virgin PLA (vPLA). Gears with varying tooth counts were designed based on commercially available models and printed using optimised printing parameters, including layer height, infill density and nozzle temperature. The performance of polymer gears depends on several engineering characteristics, including wear resistance, running load, speed, and operating temperature. To assess these factors, sound, temperature, wear loss, wear rate, and service life were measured using a custom-built testing machine at rotational speeds of 500, 1000, and 1500 rpm under a torque of 1.5 Nm. The results were compared with those of injection-moulded PLA and nylon gears under the same testing conditions. The experimental findings revealed that the rPLA gears exhibited the poorest performance across all measured metrics. In contrast, the blended PLA gears demonstrated wear characteristics similar to those of the vPLA gears, although they still fell short of the performance of the injection-moulded gears.