my 550 came with the spare tire option - so i don't know if everyobdy's car has the jack and lug wrench, but here goes. the wrench came with two sockets that fit it. one is 22mm and that's the only one of the bunch that fits the lug nuts. the other one is a reversible socket that's 17mm on one side and 19mm on the other side. what's the reversible 17/19 socket for? also, anybody know what the correct torque is for tightening the lug nuts? in its table of torque values, the service manual lists 98Nm (72.3 lb-ft) for "Wheel fastening bolt". is that the lug nut? thanks, doody.