AG Mechanics CDE Practice Exam

Most small engine manufacturers recommend __________ for temperatures above 40 degrees.

1. SAE 10W-30

2. SAE 20W-50

3. SAE 30

4. SAE 5W-30

The correct answer is: SAE 30

Small engine manufacturers typically recommend SAE 30 oil for temperatures above 40 degrees because it is rated for warmer temperatures. SAE 10W-30, SAE 20W-50, and SAE 5W-30 oils are all rated for lower temperatures and may not provide adequate protection for the engine at higher temperatures. While SAE 10W-30 and SAE 5W-30 may seem like reasonable choices, as they have a lower "W" (winter) rating, they may not provide enough lubrication and protection for the engine in the heat. SAE 20W-50, on the other hand, is rated for much higher temperatures and may be too thick for the engine to properly circulate. Therefore, SAE 30 is the recommended choice for temperatures above 40 degrees.