Mazda is marking the 40th anniversary of its first rotary engine powered vehicle on Wednesday (30 April).

By the end of April 2007, the automaker had manufactured about 1,970,000 rotary vehicles since production first began with the Cosmo Sport RE in 1967.

President and CEO Hisakazu Imaki said: "We will continue our research and development of the rotary engine. The hydrogen rotary engine holds great promise and, in fact, is already running on public roads."

After the Cosmo, Mazda launched the Familia (exported as the RX-2) Rotary Coupe, Savanna (RX-3), RX-7 and Eunos Cosmo.

Mazda is now developing its hydrogen RE, which emits no carbon dioxide (CO2). Development started in 1991 and has so far produced the RX-8 Hydrogen RE, which in February 2006 became the world's first to be commercially leased. Currently, seven are on the road in Japan under commercial lease.