Among the tests required by European and American specifications for motor oils, there is a test of the corrosion resistance of copper-lead bearings (Table 1). These tests are performed in single-cylinder Petter W1 L engines or Labeco CLR engines (Table 2). The corrosion results obtained with the Fetter W1 L engine, for calibration oils, are given (Table 4), and the corrosion curves as a function of time are shown in Fig. 1. By using the same oils, a GFC(5) working group responsible for developing laboratory preselection test methods has developed a test based on the determining of the corrosion of a lead coupon, in the presence of copper, submerged in the lubricant to be evaluated, when this lubricant is subjected to severe oxidation conditions, in the presence of air, at high temperature (Fig. 2). The results obtained are in excellent agreement with results obtained using engines (Table 5 and Fig. 3). Likewise, these tests highlight the excellent repeatability (Fig. 4) and the excellent reproductibility (Figs. 5 and 6) of the laboratory method.