A bearing for an electronically controlled throttle motor in an automobile filled with a grease composition with a kinetic viscosity between 40 and 150 mm²/sec (at 40 C.) containing (a) a straight-chain perfluoropolyether oil with a kinetic viscosity less than 25 mm²/sec (at 40 C.) expressed by the formula RfO(CF₂O)_p(C₂F₄O)_q(C₃F₆O)_rRf (where Rf is a perfluoro lower alkyl group, and p, q and r are integers whose total is between 25 and 45), (b) a base oil containing a straight-chain perfluoropolyether oil with a kinetic viscosity greater than 250 mm²/sec (at 40 C.) expressed by the formula RfO(CF₂O)_p(C₂F₄O)_q(C₃F₆O)_rRf (where Rf is a perfluoro lower alkyl group, and p, q and r are integers whose total is between 80 and 200) and (c) a polytetrafluoroethylene filler.