Sag is not normal.
Not sure if your suspension is sagging? You can generally tell just by stepping out of the car and taking a look. Compare the look of the unloaded vehicle to the look of the same vehicle when it’s fully loaded.
If the front or rear of the car seems to be lower than the other, you have some suspension sag, and it needs to be addressed.
You might need a little suspension help from us here at Airbag World.