Why is the phrase "Aluminum has more kinetic energy" thrown around so much? OK, some carbons are lighter than aluminum of the same spine, but not all. You can get carbon arrows in the 10 and 11 gpi range just as aluminum. It's not the material that generates the KE, it's the relationship of speed and weight. For this reason, I just don't agree with that statement. Sorry....didn't mean to hijack, it's just a phrase I see alot.