Ship weight

hi, someone correct me if i say something wrong, but this is my understanding of the weight system.

each hyperspace engine you build gives you a weight allowance of 1600
the items in your ship's inventory and the things you build on your ship and well as the overall size of you ship all add to your weight.
you can still hyperspace jump if you go over that weight, but your fuel efficiency will go down the more you are over the weight. you will use more of your hyperfuel for each jump

to give you an example, when i had one engine, i was at 2400/1600 and my hyperfuel efficiency (click on your hyper engine) was 4.5
i built a second engine, and went to 2400/3200. my efficiency went to 9.1