Measuring additives in lube oils is quite a common technique. The decision, which kind of system and technology ( EDRFA or WDRFA) to use, depends on sample throughput and accuracy. However, some new developments are able to reduce costs, make it faster and even more reliable. In product flows oils can be measured online with a new flow system. This can save costs. A lot of aspects of lube oil analyses with xrf are discussed. Controlling the properties of lubricating oil requires elemental chemical analysis. Oil additives usually contain Mg, Si, P, S, Cl, Ca, Cu, Zn, Mo and Ba. Due to specified levels of these elements in the product, monitoring is required. Wet chemical methods are seen to be too operator-dependent and require a relatively high degree of skill to produce accurate data. Techniques such as AAS and ICP-OES are costly and also require a dedicated skilled operator. XRF produces fast, cost effective, precise and accurate data with a minimum of operator dependence and minimal sample preparation. Different norms describes the testing method for p.e. phosphorus, sulfur, calcium and zinc in lubricating oil by different methods of x-ray spectrometry. This is nothing new. It is always depending on the requested sample throughput and accuracy , which kind of spectrometer-type and technique is recommended. A new type of approach is to make the analyses independent from possible interfering substances like oxygene which can not be measrured, as well as the organic matrix, directly. On the other side, a not know technigue for XRF, called fingerprint, can be used to see small differences and changes in the composition which is not directly based on concentrations values of the additives. It compares measured “unknows samples” with a database of listed and measured known samples. The keywords here are “main component analyses” and “Chi2 –comparision” with possible cluster analyses. This can be applied in product development and in quality control as well. It is not limited to fresh oil but can be the base for used oil measurement with wear metals. The newest development in x-ray spectrometry is to make it possible for controlling liquid product streams. For this, a flow system is introduced to maintain product flows for all kind of applications. It consists of a EDX measurements unit, a flow cell (adapted to the specific requirements) and a software package which allows to manage the data in the control room. It is not limited to a number or group of elements. XFlow.