The Bernardini MB-3 Tamoyo, a Brazilian main battle tank developed during the 1970s and 1980s, aimed to modernize the country’s armored forces and reduce reliance on foreign imports. Built as a domestic replacement for the aging M41 Walker Bulldog tanks, the Tamoyo featured a 90mm cannon in its initial iterations, later upgraded to a 105mm NATO-standard rifled gun in its Tamoyo III version, giving it the firepower to engage contemporary threats effectively. The tank utilized a reinforced hull and turret based on the M41’s design but incorporated advanced armor and modernized systems for increased protection and operational reliability. Powered by a 500-horsepower Detroit Diesel engine, the Tamoyo achieved a top speed of 65 km/h, offering excellent mobility for Brazil's varied terrain. Its fire-control system included optical and thermal sights, enhancing its combat effectiveness under diverse environmental conditions.

The Tamoyo sought to compete with tanks like the American M60 Patton and the German Leopard 1, both of which prioritized firepower and reliability. The Leopard 1 emphasized speed and advanced optics but lacked the armor protection offered by later designs. Meanwhile, the M60 Patton provided heavier protection and a similar 105mm gun, making it a tough competitor for export markets. Compared to Soviet counterparts like the T-55, which dominated global export markets, the Tamoyo offered better optics and NATO compatibility, though it struggled to secure buyers due to limited production and higher costs.

Despite its technical merits, the Bernardini MB-3 Tamoyo never entered mass production, as Brazil prioritized other armored vehicle projects like the EE-T1 Osório. The Tamoyo project, however, demonstrated Brazil’s growing capability in indigenous tank design and production, influencing subsequent efforts to modernize its armored fleet. While it remained a prototype, the Tamoyo highlighted the challenges of competing in a global arms market dominated by established powers and underscored the importance of domestic innovation in defense development.