The SP Series is the latest addition to Subaru’s line of air-cooled engines, offering advanced overhead cam (OHC) technology for improved performance and longevity. Designed for light commercial and residential engine markets, SP Series engines provide increased power and easier starts while minimizing noise and emissions, making them suitable for use with pressure washers, generators, pumps, go-carts, and various lawn and garden equipment. The Series includes the 5.7-hp (4.2-kW) SP170 169 cm³ displacement engine as well as the SP210 211 cm³ unit offering 7 hp (5.2 kW). Both feature chain-driven OHC technology and a hemispherical combustion chamber for improved engine performance. Intake and exhaust valves are positioned to lower resistance for the air/fuel mixture, while a high compression ratio produces greater power and torque. Fewer moving parts and rigid mufflers reduce mechanical noise.