Catalyst Experience on Motorcycles -- Catalyst technology has been utilized successfully on motorcycles and mopeds for over 10 years. During that time, over 15 million two- and three- wheel vehicles have been equipped with catalyst systems. Taiwan was the first country to establish catalyst-based standards in 1992 and it subsequently tightened its standards twice more in the 1990s. Based on the resounding success of Taiwan’s pioneering program and the effective performance of catalyst technology, other countries around the world have adopted or are planning to adopt control programs based on the use of catalyst technology, including Thailand, India, Malaysia, China, Japan, and countries in the European Union. Also, as EPA points out in its proposal, catalyst technology has been employed in some applications on both small two- stroke engines and large four-stroke engines.
Catalyst Emission Control Capabilities -- Catalyst technology applied to two-stroke motorcycles and mopeds has demonstrated a capability of reducing emissions in the range of 50- 60 percent for HC and 50-80 percent for CO, as reported in SAE Paper No. 2001-01-3814. If secondary air injection is used, control efficiencies in excess of 90 percent for both HC and CO can be achieved. For four-stroke engines, a three-way catalyst can achieve in excess of 90 percent HC+NOx and CO emissions.
Catalyst Durability – MECA member companies are designing and manufacturing catalyst technologies to successfully meet demanding durability requirements throughout the world. Catalyst technology has demonstrated outstanding durability on two-stroke engines, as shown in Figure 1, and on four-stroke SI engines as well. Indeed, catalyst manufacturers supplying the motorcycle market in Asia note that it is not uncommon for the two-stroke engine to fail before the catalyst.
September 17, 2002