The exhaust emissions of two and three wheelers contribute to a major extent to the pollution in urban areas of South East Asia and especially India. Most of this class of vehicles are equipped with 2 stroke engines, which operate constantly rich, - leading to high carbon monoxide and hydrocarbon emissions. On the other hand the NOx concentration in the exhaust gas is neglegible.In near future more stringent exhaust gas legislation get effective in a number of countries. Therefore catalytic aftertreatment devices are necessary to meet the emissions limits. Hot Tubes™ and/or monolith type catalysts can be applied. The high exhaust gas hydrocarbon concentrations lead to high exotherms on oxidation which drives the exhaust gas temperatures up to a range between 750 and 850°C. Therefore thermal ageing of the Hot Tubes™ and monolith type catalysts is severe. The design of advanced catalyst systems has to take this into account.Due to their high catalytic efficiency and excellent durability the new type catalysts are applicable for current and upcoming emission regulations for the European Union, India and South East Asia.