Rocar DAC was a series of buses and trolleybuses produced by the Autobuzul (later Rocar) company of Bucharest, Romania, between 1979 and 2000. They were available in both standard 12-meter models and articulated, 17-meter models. The first examples to enter service were DAC 117UDs that were made towards the end of 1978 and entered service with the ITB in Bucharest in April 1979.

Rocar DAC
Rocar DAC 112 UDM in Târgu Jiu, 15 June 2019. As of 2021, only one city in Romania still operates the elderly bus type: Târgu Jiu.
Overview
Manufacturer	ROCAR
Production	1978-2000
Body and chassis
Doors	1, 2, and 3
Floor type	step entrance
Chassis	12 m rigid or 17 m articulated
Powertrain
Engine	Rába D2156 HMU 192 hp, or 240 hp in turbo charged version
Power output	192 hp aspirated, 240 hp turbocharged
Transmission	4 or 6 steps gearbox
Dimensions
Length	12 m rigid, 17 m articulated

For much of the 1980s and early 1990s, these buses and trolleybuses were the backbone of the urban transportation network of Romania since, throughout the 1980s, public transportation companies were not allowed to import any type of vehicle.

The buses were designed and built in a period of severe shortages, the main emphasis being put on economizing material usage and simplicity of the design. Most buses of this type did not have power or assisted steering, and only a small number of buses, built in the early part of the project (1979-1982) employed automatic gearboxes, which were abandoned as solution due to high costs. The passenger area was also very spartan, having no interior sound or display systems, seats being built out of plywood, only later models were fitted with plastic seats, light fixtures being 6-8 small 12-volt light bulbs providing insufficient lighting.

During the late 1980s, some were converted to run on methane gas, by installing two or three gas tanks on the roofs. After the fall of the communist regime, the buses were converted back to diesel. DAC buses were equipped with Hungarian RABA-MAN engines, or with Romanian IABv engines capable of 192 horse power DIN and a 4 or 6 gears gear box for a maximum speed of 65 km/h. After 1990 the series was slightly improved as quality level, like RABA engines, RABA transmission, plastic seats (or sometimes with vinyl upholstery cushions - mainly coach versions, but also some urban versions), and many models were taller. Some of them, were even fitted with fluorescent lighting, but in very few cases, this retrofitting was mainly made at the host garage. Some models were fitted after the 1990s with less polluting motors, and this thing was specified on the bus.

In 1996, Rocar began replacing the model line-up with the new Rocar De Simon range that was produced until the bankruptcy of the company in 2003 (however, Dac 112 UDM buses were built until 2000). Most Rocar DAC buses have been withdrawn from service, and replaced with more modern buses. RATB still uses them as utility or service vehicles (the last examples being withdrawn in 2007), but not any more as passenger vehicles. However, some survived with smaller transport companies, on some rural services and in small towns.

Trolleybuses, on the other hand, have fared better, because of the higher purchasing cost and durability, and are still a common site in cities such as Cluj (withdrawn in 2016), Targu-Jiu or Kyiv (withdrawn in the mid 2000s), however there are plans to replace them with newer vehicles. In some cases trolleybuses exceeded 25–30 years of service. Târgu Jiu's last Rocar DAC trolleybuses, which had operated since the network was opened in 1995, were finally withdrawn from service in December 2021, after new Solaris Trollinos arrived to replace them.

It was also exported, only as trolleybus version, in Bulgaria (used in Varna, Burgas, Sofia) and Ukraine (Kyiv, Kharkiv, Dnipro), however they were modified and fitted locally with other motors and controllers than in its mother country. Also sent as test vehicles in former Yugoslavia, Czechoslovakia and Hungary, but were not accepted (probably mainly due to the fact that these countries were also having their bus manufacturers - IKARBUS, Škoda and Ikarus respectively).