Fuel economy regulations have been issued in many countries to save energy,and it is one of the most essential performance requirements for Passenger Car Motor Oil(PCMO) this decade.The performance is also important to reduce green house gas(GHG) emissions.Automotive,Oil and Additive industries have been developing fuel economy tests in fired engine for PCMO.The ASTM 5 Car test was started in 1982 and ASTM Sequence Ⅵ series test was also developed by the industries as one of fuel economy tests after the 5 Car test.However,the fired engine(combustion) test condition is more complicated and the combustion mode in engine introduce high variability into a fuel economy measurement.Screening by bench testing is complicated by the difficulty to reproduce friction conditions of all of engine parts.Based on the background,a motored engine friction torque test(MEFT) was developed as one of the solutions for fuel economy screening test.Using a newly developed MEFT,key additive chemistries were evaluated and compared in the test,and it distinguished the differences in additive chemistries,in addition to those in viscosity and friction modifiers.The Sequence Ⅵ-D FEI 1(Seq.Ⅵ-D FEI 1) and chassis dynamometer vehicle tests were also conducted in this study,and the test data has shown an excellent correlation among MEFT,Seq.Ⅵ-D FEI 1 and chassis dynamometer vehicle tests. Fuel economy regulations have been issued in many countries to save energy, and it is one of the most essential performance requirements for Passenger Car Motor Oil (PCMO) this decade. Performance is also important to reduce green house gas (GHG) emissions. Automotive , Oil and Additive industries have been developing fuel economy tests in fired engine for PCMO. ASTM 5 Car test was started in 1982 and ASTM Sequence Ⅵ series test was also developed by the industries as one of the fuel economy tests after the 5 Car test. However, the fired engine (combustion) test condition is more complicated and the combustion mode in engine introduce high variability into a fuel economy measurement. Screening by bench testing is complicated by the difficulty to reproduce friction conditions of all of engine parts. Based on the background, a motored engine friction torque test (MEFT) was developed as one of the solutions for fuel economy screening test. Using a newly developed MEFT, key additive chemistries were evaluated and compared in the test, and it distinguished the differences in additive chemistries, in addition to those in viscosity and friction modifiers. The Sequence VI-D FEI 1 (Seq. VI-D FEI 1) and chassis dynamometer vehicle tests were also conducted in this study, and the test data has shown an excellent correlation among MEFT, Seq. VI-D FEI 1 and chassis dynamometer vehicle tests.