When evaluating a hydraulic engine hoist, the most critical factor is the lifting capacity, typically ranging from 0.5 to 3 tons. You must verify the boom reach and height range to ensure it can clear the vehicle's engine bay. Look for heavy-duty steel construction with a powder-coated finish for corrosion resistance. Additionally, prioritize models with 6-wheel 360-degree swiveling casters for maximum maneuverability under load, and ensure the hydraulic cylinder (ram) features a safety bypass system to prevent over-extension.