When selecting a tricycle, the engine displacement (typically 150cc, 200cc, or 250cc) is the primary factor for performance. For passenger transport, ensure the chassis is reinforced with high-strength steel to handle heavy loads. Pay close attention to the braking system (front drum/rear hydraulic disc) and the cooling system (air-cooled vs. water-cooled); water-cooled engines are superior for tropical climates to prevent overheating. Additionally, verify the fuel tank capacity (usually 12L-15L) to ensure operational efficiency for commercial use.