Abstract Diesel combustion engines, due to their high efficiency, continue to be attractive powertrains to fulfill existing and future emission standards concerning carbon dioxide (CO2) and fuel consumption. One main aspect for fulfilling emission targets is the use of highly efficient injection systems operating at high pressure levels of up to 2.500 bar and more. In order to ensure the safe and reliable functioning of these hightech injection systems, the reduction of contamination in the diesel fuel system using highly efficient filter systems is very important. This reduction of contamination consists on the one hand of the filtration of particles, and on the other hand in separation of water droplets out of the diesel fuel. Existing and upcoming highly efficiency filter media show outstanding performance results under severe test conditions either on the test bench, or in field conditions. In order to continue to be able to provide solutions suited to challenging installation packaging, either in the engine bay, under the floor, or near the fuel tank, the existing technology and designs for particulate diesel filtration and water-diesel separation have to be transferred and adapted to modular and flexible design concepts. The new particle fuel filtration concept consists of several small filtration cells where fuel is filtered in parallel through each cell. The small filtration cells allow an individual configuration, and offer the car manufacturer maximum flexibility in terms of packaging and positioning in the vehicle. In this paper an overview of the different new flexible particle filtration concepts will be shown. Furthermore some results from the simulation calculations and some first test results will complete the technical insight into the development phase of these new flexible filtration concepts. The second part of the paper focuses on the new horizontal diesel-water separation concept that is especially designed for underfloor installations spaces where the existing and very well established three-stage diesel water separation shows limitations in terms of packaging. This underfloor diesel-water separation concept is intended to be used as an option for regions with bad fuel quality or high water content in the diesel fuel distributed in the market. The use of diesel fuel filter systems with a very high performance protects modern injection systems and can therefore also be used in areas where the quality of the fuel is poor. Consequently the availability of highly efficient fuel filter systems is an important key factor to the global entry of modern diesel motor technology in growth markets such as Asia, Russia or South America.