Here's how the different oil grades compare:
5W-20: Ford's recommended viscosity and the best choice for normal operation.
5W-30: Slightly thicker at operating temperature, but not the specified grade.
10W-30: Thicker during cold starts and at operating temperature. I wouldn't recommend it for a complete oil change.
10W-40: Considerably thicker and not recommended for this engine.
If you're simply topping off an engine that's low on oil, a small amount of compatible 10W-30 would generally be preferable to running the engine with insufficient oil. I would not use either 10W-30 or 10W-40 for a complete oil change.
Nov 2, 2026 at 7:25 AM