Out of the box, I ran my 110 lbs. Golden and my 85 lbs mixed breed up the ramp with little problems, it's coming down that takes a little getting used to!  Seems well built and strong, but the non skid surface is already scratched up after only a few uses.  My dogs seem to be getting the hang of it, though.  Next will be my German Shepherd Dog, who has never been in my truck, should be a challenge.  Just a note, the side walls could be a little higher, but they work okay.