Agitators and impellers are both found in top load washers. However, they function differently from one another.  Agitators use a tall and central spindle that twists back and forth, rubbing against clothes to remove stains. On the other hand, impellers use a low-profile cone or disc that rotates to help rub clothes together.  Most websites and personal blogs will often tell you that agitators are more reliable because they’re far older than impellers. However, even though agitators provide shorter wash times, they’re usually harsher on clothes than impellers.  In fact, impellers deliver a gentler and more thorough cleaning. Moreover, impellers usually use less motion and water than agitators. That being said, you can’t go wrong with either one.