What type of oil does the loader use?

• A. 5W-40
• B. 15W-40
• C. 10W-30
• D. 20W-50

Answer: (B)

Oil viscosity is about how the oil flows when cold and when hot. The first number with W (winter) shows cold-start flow: the lower that number, the thinner the oil at cold temperatures, which helps start and initial lubrication. The second number shows how thick the oil is at engine operating temperature; higher means a thicker film at heat, giving better protection under stress.

For a loader doing heavy work across a range of temperatures, 15W-40 provides a practical balance: it flows well enough to lubricate on cold starts, while staying viscous enough at high operating temperatures to protect engine components during heavy loads. The other grades tend to be either too thin under load (risking wear when hot) or too thick for easy startup and efficiency. Always follow the OEM recommendation, but 15W-40 is a common, versatile choice for many diesel loaders.