* 5W-20: This is a common recommendation for many 2003 Ford Explorers, particularly in moderate climates. It's a good all-around choice.
* 5W-30: This might be recommended for hotter climates or if your owner's manual specifies it.
Crucially, check your owner's manual. The manual will specify the weight and type (conventional, synthetic blend, or full synthetic) recommended by Ford for your specific vehicle. Using the wrong oil can damage your engine.
