It is used by many vehical models as a sub-model of the vehical (Impala SS, Mazda Protege ES, Boniville LS...etc.)

With the Oldsmobile, the LSS was originally going to be a sub-model of the Eighty-Eight. The LSS became a stand alone production (Proud Owner =) ) branching off of the Eighty-Eight.

When becoming an LSS, certain upgrades need to go into effect to do so. Evolving from the Eighty-Eight to the Lss, the susspension was stiffened to give a more sporty ride (while still maintaining a smooth cloud like ride) and upgrade handling abilities. The engine remained the same (3.8L V8) producing 225BHP and 240LB Torque; but, the LSS had the option for an upgrade to a supercharged version of the same 3.8L engine-now producing 240-250BHP and 280LB Torque. The LSS had many other various upgrades, but that is not what this question is about.

Back on topic... LSS=Luxury Super Sport.