Originally Posted by
Epstein
As far as weight, simple 4/6pt cages are (very) generally a couple dozen pounds. This foam I used is 8 pounds / cubic foot. 1 cuft is 957 fl ounces. I put about 180oz of liquid component in to the car, which expanded to about ~400 fl oz worth of space. So I added about 3.5 pounds to the car. I probably need to add 2 more pounds before I finish.
Also that 5.5-6lbs is spread over the car, not concentrated in one point. So your basically adding a feather of weight in the car.