Future stringent emission legislation will require high efficient catalytical systems. Along with engine out emission reduction and advanced wash coat solution the substrate technology will play a key role in order to keep system costs as low as possible.The development of metallic substrates over the past few years has shown that turbulent-like substrates increase specific catalytic efficiency. This has made it possible to enhance overall performance for a specific catalytic volume or reduce the volume while keeping catalytic efficiency constant.This paper focuses on the emission efficiency of standard, TS (Transversal Structure) and LS (Longitudinal Structure) metallic substrates. In a first measurement program, standard TS and LS substrates have been compared using a 150cc 4 Stroke engine in dynamic (ECE R40) conditions. In a second test standard and LS substrate have been tested.Both TS and LS technologies show advantage compared to standard technology but have different application fields: TS is a cost effective solution for next emission limits while LS is a possible solution for future stringent emission limits.