After the opening of the O-Bahn Busway to Paradise Interchange in 1986, the South Australian Government realised that they would be short of buses when the extension to Modbury Interchange was complete. The S.T.A. approached Mercedes Benz for a further 10 buses to add to the existing Mercedes fleet of 90 buses, however Mercedes were only prepared to do another bulk order of 100 which the S.T.A. could not afford or justify. Therefore negotiations were made with M.A.N. and P.M.C. body manufacturers to make an alternate articulated bus design. The end product was the M.A.N. SG280H, a body design specific to Adelaide but modelled on existing SG class features. The prototype bus 1941 was completed by P.M.C. on the 27th August 1986 and was to mark the manufacture of 40 Buses (1941-1980). The project was funded under the Commonwealths Bicentennial Transport Program for 1988. The Adelaide fleet fell under the “Federally Funded Bus Acquisition Programme” within the Australian Bicentennial Road Development (A.B.R.D.) Act and commenced production throughout 1987. The buses were part of two programmes for South Australia; the production of 40 buses for O-Bahn and suburban transport, and the construction of a rail/bus Interchange at Salisbury Station to become Salisbury Interchange This would link the Gawler Rail line to the outer northern trunk routes and rail feeder services within the Parliament’s 1983 funding of Road Development Projects.

The Buses had quite a colourful history, receiving over 7 different liveries in  their lifetime. The first was the green and gold representing the Commonwealth  colours. All 40 buses were delivered in this  livery. Around 10 buses received the O-Bahn blue and green stripes and were fitted with  guide wheels to aid the Mercedes fleet, but their time was short lived as the rear steer function caused tyre scrubbing on the  Busway. In 2006 they made a brief return. 

A majority of the fleet were then painted  into the STA/TA blue and red Speed  stripes in the 1990’s. After the mid 1990’s, some depots were operated by different companies; one was Hills Transit at Aldgate, and bus 1969  was the only MAN artic to receive the teal  and yellow “Hills stripes”. Around the same time, SERCO from England took over 3 depots, Elizabeth, St Agnes  and Morphettville. Serco had 2 different liveries for their buses; one was grey and red speed stripes, the other were horizontal grey, red, and blue stripes on a white  body. Before the year 2000, TransAdelaide  no longer operated the Adelaide bus system and each depot came under private contract operations. After 2000, the entire fleet SG was converted to the Adelaide Metro livery.

The M.A.N. artics played a major role in Adelaide’s transport. Adding to the articulated fleet, they were a common runner for Football Express services, the Sky Show, Royal Adelaide Show shuttles, school bus routes, After Midnight and New Years Celebrations, and at the end of their career served as rail  replacement buses for the Noarlunga Line electrification. 

During the time of Serco and eventually Southlink, a majority of the fleet operated out of Elizabeth Depot and provided services along the Northern 22 series trunk routes, and the northern 400 series rail feeders. The remaining buses worked with Torrens Transit operating east and west services and 3 buses remained in the hills at Aldgate.

The design of the buses was modelled similar to the SL200 buses of 1982, with more modern design features including large electronic destination screens at the front and rear, square headlights, rear horizontal exhaust stack, and a turbo fitted to the engine. 

In 2013 the whole fleet was transferred to Lonsdale Depot and were used for just over a year on the Noarlunga Line rail substitute services. They operated for a short time with the remaining Mercedes-Benz articulated units. In 2014, the entire fleet was returned to Elizabeth Depot to await their future use or disposal. 

1954 was bought in 2016 by a to-be BPASA member, and repainted into its “as delivered” stripes the same year. It is the first preserved SG280H to be fully restored.