The second-generation X5 has grown. It is 7.4 inches longer, 2.4 inches wider and as inevitably as the Patriots seem to make the playoffs heavier at 5151 pounds, up 218 pounds from the first V-8 engined X5 we tested. The new, larger footprint has allowed BMW to add the seemingly obligatory third-row seat, which is fine for small kids on short journeys but tight for grownups. Still, with this row folded, there are now 19 cubic feet of cargo room, an increase of three cubic feet.