When procuring an oil trailer, the tank material is the most critical factor; options include carbon steel (Q235B) for cost-effectiveness, aluminum alloy (5083) for lightweight and corrosion resistance, or stainless steel for high-end chemical transport. You must verify the tank thickness, typically 5mm to 6mm, and ensure the inclusion of anti-wave baffles every 1.5 to 2 meters to maintain stability during transport. Additionally, check the axle brand (e.g., FUWA or BPW) and suspension system (mechanical or air) to ensure the trailer can handle the intended load capacity, usually ranging from 30,000 to 60,000 liters.