When sourcing a used wheel loader, you must prioritize the engine condition and hydraulic system performance. Check the rated load capacity (typically ranging from 3 to 7 tons for standard construction) and ensure the engine brand (such as Weichai, Cummins, or Caterpillar) aligns with your local maintenance capabilities. Inspect the operating hours; generally, machines with under 5,000 to 8,000 hours offer the best balance between price and remaining service life. Additionally, verify the bucket capacity and the integrity of the articulated joint, as excessive play here can lead to significant repair costs.