bus (diesel/electric) based on the O405. The O405 trolleybus was presented in that same year. In 1984, a trial was carried out with a four O305 buses already in use in Auckland, New Zealand, with two powered by liquid petroleum gas and two powered by compressed natural gas (CNG). At the same time, two Volvo B10M buses were converted to run on methanol. All six, as well as a further 50 O303 and O305 buses, were all put onto CNG. Auckland City had a fleet of one hundred O303 buses and three hundred O305 buses. In the 1990s three new natural-gas-powered models were unveiled by Mercedes-Benz: the O405 GN GNG low-floor articulated bus, which was Europe's first natural gas low-floor city bus; the O405 NG solo city bus and the O405 ÜNG for rural service. All models were fitted with the M-447 hG engine that was exported from Brazil. In 1994 a prototype of a low-floor articulated duo bus based on the O405 – the O405 GNTD – was presented, featuring electric hub motors. In 1996 the OH-1315 natural-gas bus chassis is succeeded by the OH-1621 LG, also natural-gas-powered. One year later, the OH-1621 LG was equipped with an electronic-managed engine as standard. In 1997 Daimler-Benz presented its first fuel-cell bus, designated NEBUS (New Electric Bus), based on the O405 urban bus. It was the world's first fully operational fuel-cell-powered bus. Another fuel-cell-powered was developed later, based on the Citaro. Exemplars of the Citaro Fuel Cell bus are currently being tested in Europe, China and Australia. In 1998, the Cito (a diesel-electric midibus) was unveiled, featuring the low-floor concept. In 2000, Mercedes-Benz do Brasil delivered the first 56 model M-447 hLAG turbocharged natural gas engines to the city of Hannover in Germany fitted to specially-designed Citaro citybuses for EXPO 2000. Subsequently, this engine has sold in larger numbers compared to the previous M-447 hG engine, with over 600 ordered by Australian bus operators alone. Products Minibuses Sprinter 1995–present Vario 1996–2013 Medio 2000–2005 LO Series 1932–present Full-size buses LPO 322/457 1962-1966 O317 1958–1977 O321 1954–1970 O322 1959–1964 O326 1958–1969 O302 1965–1974 O303 1974–1992 O305 & O305G 1969–1987 O307 1973–1987 O309 1967–1986 O321 1954–1970 O340 1992–1999 O352 1960–1970 O355 1972–1978 O362 1975–1979 O364 1979–1986 O365 1984–1988 O370R, O370RS, O370RSD 1984–1987 O371U, O371UP, O371UL, O371R, O371RS, O371RSL, O371RSE and O371RSD 1980–1990 O400UP, O400UPA, O400R, O400RS, O400RSL, O400RSE and O400RSD 1994–2001 O404 1992–1999 O405,