In API engine oil licensing, a candidate oil must meet the performance requirements of category defined engine tests. The reason for the engine tests is to assess the capability of the candidate oil in field performance. Unfortunately, due to the time consuming and expensive nature of most engine tests, a candidate oil is typically run only once or twice in an attempt to meet the performance requirements. Given that the results from most engine tests have large amounts of variability, the assessment of the candidate oil in several tests, although adequate, is obviously not perfect or inexpensive.
The Virtual Engine Test is a process in which the time and expense of category defined engine tests may be reduced while maintaining, or even improving, the assessment of the candidate oil capability. In Virtual Testing, candidate oil performance is determined, not by the test results in the physical engine test on that oil, but by an empirical model based upon test results generated in the engine test for similar oils. The empirical model, in other words, predicts candidate oil capability.
The advantages of Virtual Tests include reduction in common and special cause variability, test time, and test expense in oil assessment. Several case studies and simulation examples are presented that show how a Virtual Test has the potential to assess the capability of a candidate oil better than an actual engine test result.