engine compartment. Variants Production marks Urutu Mk I: First production model to enter service with the Brazilian Army in 1975. Powered by a 174 hp (130 kW) Mercedes-Benz engine with a manual Clark transmission. This variant also lacked propellers; water propulsion was accomplished by use of the wheels. Urutu Mk II: Second production model, which replaced the Clark gearbox with a Mercedes-Benz 63/40 gearbox but was otherwise identical to the first mark. Urutu Mk III: Third and by far most common production model, which incorporated an Allison MT-643 automatic gearbox and a Detroit Diesel 6V-53T 6-cylinder water-cooled diesel engine. Urutu Mk IV: The final production model introduced by Engesa, which offered the option of a 190 hp (142 kW) Mercedes-Benz OM 352 engine and an Allison AT-540 automatic gearbox. Other possible options included various Mercedes engine and Allison gearbox combinations. Other variants Engesa produced a wide variety of variants which grafted modifications on its basic production models; of these the Uruvel is the most well-known, but the others went largely unnamed and were often designated according to their intended role. Uruvel: Also known as the Urutu Armored Fire Support Vehicle, the Uruvel was developed for a US Army program during the 1980s aimed at creating a multi-purpose, air-portable wheeled armored vehicle capable of delivering direct fire support as needed. It was a baseline Urutu modified with a large turret ring to accommodate the Cockerill Mk.III 90 mm cannon and EC-90 turret of the EE-9 Cascavel. The Uruvel was first publicly unveiled in 1985; it could seat four infantrymen in addition to a driver and two-man turret crew. EE-11 Mortar Carrier: Urutu modified with an 81 mm mortar in the troop compartment; the mortar is fired through a hatch in the hull roof. The mortar could be elevated from +40° to +80° and was designed for quick disassembly as needed. A 7.62mm general-purpose machine gun is mounted on the hull roof for self-defense. EE-11 Ambulance: Urutu equipped with four stretchers, a freezer, and medical equipment, as well as a raised roofline, with the troop compartment redesigned for casualty transport. EE-11 Riot Control: Turretless Urutu equipped with a bulldozer blade for clearing street barricades. EE-11 Recovery: Urutu modified with a hydraulic crane and towing winch, portable generator, and increased internal stowage for accommodating power tools and welding equipment. EE-11 Anti-Tank: Urutu fitted with a one-man turret housing a 25 mm autocannon capable