My hitch has a tough weight of 200lbs but I found one website that says the civics max tounge weight is 100lbs. What harm will it do if I got over it 20/50 lbs?

 

welcome to the forum. just more ware and tare on your rear suspension and wheel lugs, also engine/trans. it may never show up, but if things start to fail sooner, you will know why.

 

If you overload the gross axle weight rating, it will cause the tires to misalign, making them wear out faster. It can also case suspension failures if you hit a bad bump really hard, and it can make the car less stable to drive. It will also cause the suspension to bottom out much more easily than usual, and I'm sure I don't have to tell you that a suspension spring is much softer than a bump stop.