The Ford Explorer is not a full size SUV but technically a midsize SUV. The Ford Expedition is the Explorer’s larger full-size SUV sibling. Modern midsize SUVs usually (but not always) have a third row, though some, like the Honda Passport, trade in the third row for added cargo space.
The Ford Explorer is bigger than the Chevy Equinox by almost every metric—there’s more head, shoulder, hip, and leg room. But the Explorer is significantly smaller in cargo space behind the rear seat—you might end up playing luggage Tetris on long road trips with passengers. That’s the price you end up paying for that third row of seating.