SAE 15W-40: This oil is recommended for temperatures between -4°F (-20°C) and 104°F (40°C).
SAE 10W-30: This oil is recommended for temperatures between 0°F (-18°C) and 122°F (50°C).
SAE 5W-30: This oil is recommended for temperatures between -22°F (-30°C) and 140°F (60°C).
It is important to note that these are general recommendations, and the specific oil viscosity required for your Freightliner M2 truck may vary. Refer to the owner's manual or consult with your local Freightliner dealer for the exact oil viscosity recommended for your specific truck and operating conditions.