IF YOU LIKE AN UPVOTE !!!!!!!!

The Tamoyo is a derivative of the M41, incorporating new technologies and a 90 or 105 mm cannon, but maintaining the characteristics appreciated by the Brazilian Army in the M41. In the prototypes, several components were developed based on the M-41 parts, the suspension and running gear were similar.
Unlike the EE-T1 Osório da Engesa, it was a medium tank, and designed according to the needs of the Brazilian Army and the national automobile park, in order to reduce the dependence on imported equipment and parts. Osório was an MBT, a heavy tank, was developed for a possible order from Saudi Arabia, and incorporated several imported equipment.
Based on the operational requirements established by the Brazilian Army, Bernardini began to develop the new vehicle (1982-1983), initially the so-called X-30. Such a tank could not exceed 30 tons, a limit imposed by the Brazilian road and rail system. National companies were contacted who could supply components for the project.

Prototypes

The first prototype was finished in 1984 and was designated Tamoyo I. It had suspension by torsion bars, M32 90mm cannon, M41C, Scania DSI14 engine, rotating mechanism of the national tower, its Alisson CD-500-3 transmission (the same employed in the M-41, seeing that it was a requirement of the Army), light armor and low silhouette.
The Tamoyo II was intended to adapt the vehicle to the international market, a GE HMPT-500-3 transmission was incorporated, same as the American M-2 Bradley armored vehicles, which was coupled to the Scania DSI14 engine. The cannon would be a 105mm model, however, the 90mm M32 was maintained, coming from the M41C Caxias.
Tamoyo III featured a number of improvements, easily distinguishing itself from previous models. Tamoyo now incorporates modern technologies, such as steel and ceramic composite armor, laser rangefinder, night and thermal vision, computerized shooting direction, stabilized tower for shooting in motion. The vehicle received the modern 105mm cannon L7 Royal Ordnance and a Detroit Diesel 8V92TA engine, this engine was only for the initial stage of development, an engine with an average of 900 to 1,000hp was planned. The transmission was a problem, as the GE transmission did not support more than 600hp, and a new, more resistant transmission was still being designed, ZF had no prototypes available, so the way was to install an Alisson CD-850-6A model, the same as the M60 Patton, which met the prerequisites perfectly. The chassis and turret were modified and the frontal armor was increased, the total weight reached 31 tons.

Nationalization

With the options for a 90mm or 105mm cannon the manufacturer stated that the tank could be used both as a medium armored reconnaissance vehicle, and with the larger 105mm cannon and better armor and engine it could form groups of tanks, suitable for face any threat that could be expected in the South American subcontinent.
The Tamoyo could be equipped with a Ferranti shooting computer, while the periscope was North American, manufactured by the company Kolmorgan. Some of the systems were not installed on board the Argentine TAM tanks, which at that time were the reference for Brazilians.
The engine considered for the tank was initially the Scania DSI 14 powertrain, with the power of 550hp, manufactured by Scania in Brazil. But the possibility of using a Detroit Diesel 8V92TA engine with 750hp was also considered, in case the vehicle is exported and there is a preference for this engine.
The great advantage of Tamoyo as a possibility for a Brazilian tank was in the large percentage of incorporation of components manufactured in Brazil. All the armor, the turret, the hydraulic systems, the tracks, one of the engines and even the cannon (in the case of the 90mm) could be manufactured in Brazil. Some of the other equipment, although of international origin, could be nationalized as long as the number of systems to be purchased was sufficient and justified the operation.

Accident

After motorization tests carried out on Rodovia dos Imigrantes, one of Tamoyo's prototypes was involved in a fatal accident on January 16, 1985 when it crushed a Volkswagen Brasilia occupied by three people at the intersection of Avenida Abraão de Morais and Rua Francisco Tapajós. Two people died and the third lost a leg. Bernardini initially claimed that it was not to blame for the accident, blaming a burned traffic light as responsible for the collision and crushing. The following day, the São Paulo City Government's Highway System Operations Department (DSV) reported that the traffic light at that intersection was working at the time of the accident, pointing out the driver of Tamoyo (a mechanic from the company Bernardini who is unsuccessful in driving armored vehicles) November 1984) as responsible for it.
The accident irritated the army leadership (who blamed Bernardini exclusively for the accident) and was one of the factors in the project's cancellation.