In practice the tribological systems are much more complex and therefore cannot be reproduced on a laboratory test rig. Instead of focusing on only one or two distinct parameters, a lubricant has to provide a variety of features such as extreme pressure, antiwear, boundary lubrication, film forming properties etc. Because of this complexity, correlation between laboratory testing and field results is difficult.
Laboratory tests are in most cases the only chance to obtain information about the performance of an additive, because end users are reluctant to use their metal working machines for trials. To overcome this problem, Rhein Chemie works very close together with large Technical Institutes and Universities to obtain field test results on different metalworking operations.