Hyundai Aero City

The Hyundai Aero City (hangul:현대 에어로시티) is a heavy-duty single-decker bus manufactured by the truck & bus division of Hyundai. It was introduced in 1991. It primarily used as a city bus and an intercity bus as either a complete bus or a bus chassis. It is distinguishable by a front 'Aero City' badge, but the common Hyundai badge is usually on the rear. The model's principal competitors is the Daewoo BS106 Royal City, but it also competed against the now-discontinued Kia AM bus series (originally Asia AM).
First Generation (CY) 1991–2000.
The Aero City was launched as the successor to Hyundai RB, it is built on the Mitsubishi Fuso Aero Star chassis until 1994.
Aero City 520L
It was produced from 1991 to 1994 with the wheelbase of 20cm shorter than the Aero City 540.
Aero City 520SL
The 520SL is produced from 1991 until 1995 with low ground clearance than the 520 and 520L.
Aero City 540
The 540 became available from 1991 to 2000 as a Intercity/City bus, in late 1997 the 280 horsepower D6AB was available.
Aero City 540L
The 540L is the same as the 540 with D6AB engine and an 8-pin Front and Rear wheel design.
Aero City 540SL
The 540SL is Low Ground Clearance than the 540 and 540L.
Super Aero City (2000-2004).
The Super Aero City was launched in 2000 as successor to the Aero City 540/540L/540SL with three engine options, the diesel version is powered by D6AB still producing 280 horsepower and the Naturally Aspirated D6AV producing 235 horsepower, while the CNG version is powered by C6AB producing 290 horsepower
Super Aero City L 
The Super Aero City L has the interior elements from the Aero City 540L
Super Aero City SL
Like the Super Aero City L, the Super Aero City SL has the interior elements from the Aero City 540SL, the Super Aero City SL is only offered in Diesel powertrain.
New Super Aero City (November 2004-January 2008)
The New Super Aero City was launched in 2005 and it is offered in Diesel or CNG 
New Super Aero City L
The New Super Aero City L has integrated rear lamps and protective partitions installed in the driver's seat.
New Super Aero City SL
The Super Aero City SL is produced between December 2004 to early 2006 with a lot of interior and exterior changes such as integrated rear lamps, fixed driver's side view mirror.
New Super Aero City Low Floor
The Low Floor version of the Super Aero City was launched in 2005, CNG and automatic transmission is standard.
New Super Aero City Facelift (February 2008-Present).
The New Super Aero City was launched in 2005 with its facelift similar to the Hyundai Universe. The CD type audio system and MP3 player was added in 2010, the air suspension is now added as an option in 2012, in 2015 the Inline-six H310 Euro 6 Diesel engine is introduced.
Models.
The Aero City was built on the Mitsubishi Fuso bus chassis until 1994, when Hyundai created its own bus chassis. The Aero City has been produced under many different names. The current models include:
Past models include: