:Governing bodies world-wide are setting increasingly tighter emission standards to help improve air quality. US and Californian LEV/ULEV standards are pace setting, European Stage II legislation has just become effective. In Brazil, the upcoming 1997 standards are also demanding for tighter emission control. The monolithic ceramic honeycomb catalytic converter -for more than the past 20 years- has been a reliable key element in the automotive emission control systems.In order to help meet tightened emission regulation as well to satisfy even more stringent durability requirement, an advanced thinwall ceramic Celcor XT has been developed for increased geometric surface area and reduced backpressure. The product properties as well as FTP and ECE emission and durability test results are being described in this paper.Converter system durability is also determined by robust canning and mounting systems. A durable mounting concept, especially for preconverters, is being described. It has been tested under severe conditions of 75 g hotshake test for 100 hrs engine aging, representing 80000km European driving. In addition it has been subjected to 300 hrs engine thermal shock. The paper discusses the test procedures and the results of these tests.It is shown, that ceramic converter systems withstand these stringent tests and thus represent viable and durable concepts for emission control requirements world wide.