Wartsila Dual Fuel Engine

Wartsila dual-fuel engines are four-stroke medium-speed marine engines that run on natural gas, light fuel oil, or heavy fuel oil, switching between modes without a load break. In gas mode they burn a lean premixed air-gas charge on the Otto cycle, ignited by a small marine-diesel pilot injection, which holds NOx below the IMO Tier III limit in MARPOL Annex VI Reg.13 without exhaust aftertreatment. The platform spans the 20DF, 31DF, 34DF, and 46DF families. Methane slip from the lean-burn cycle is the residual climate penalty, and FuelEU Maritime counts that slip well-to-wake at a GWP100 of 28.