* 4.0L SOHC V6: This was the most common engine.
* 4.0L OHV V6: Less common than the SOHC version.
* 4.6L V8: Available as an option, particularly in higher trim levels.
To know the exact engine size of a *specific* 2001 Ford Explorer, you'd need to check the vehicle's documentation (owner's manual, VIN sticker) or look at the engine itself (the displacement is usually stamped on the engine block).
