Buyers should prioritize engine cooling systems (water-cooled vs. air-cooled) based on the environment. For heavy-duty industrial use, ensure the engine features slow-speed operation (650-1500 RPM), which significantly extends the lifespan compared to high-speed alternatives. Verify the alternator type, preferably brushless with AVR (Automatic Voltage Regulator) to ensure stable power output and protection for sensitive electronics. Additionally, check the fuel consumption rate (typically measured in g/kWh) to calculate long-term operational costs.