According to a recent report by The New York Times, GM is using aerospace-grade glue to assemble the new Acadia. Unlike rivets, which only bond where they’re inserted, the glue bonds the entire seam, forming a more rigid structure and allowing the individual pieces to be thinner and therefore lighter. GM says that weight savings from this technique make the new Acadia 700 lbs lighter than the outgoing model and raise the EPA estimated highway rating to 23 mpg.
Obviously building vehicles with glue is nothing new. Off the top of my head I know the Lotus Elise used glue to hold itself together with varying degrees of success. I seem to remember that the new 7-series uses something similar to include carbon fibre in its construction as well.
Still, that GM is using this kind of stuff to shave massive amounts of weight off of vehicles like the Acadia is awesome. We live in amazing times.