When sourcing a Howo (Sinotruk) engine, you must first identify the specific series, such as the WD615, D10, or D12 series. Key specifications include the horsepower rating (typically ranging from 266HP to 420HP), torque output, and emission standards (Euro II, III, IV, or V). Ensure the engine matches the vehicle's transmission interface and cooling system requirements. For heavy-duty applications, prioritize engines with forced induction (Turbocharged Intercooled) systems to ensure optimal fuel efficiency and power delivery under load.