One of the most successful models in the BMW 3 Series (E30) was the two or four-door BMW 320i Sedan. It was equipped with the smallest BMW six-cylinder engine (M20B20), which delivered its maximum output of 125 hp sonorously and silky smooth. The BMW 320i had solid basic equipment, which was constantly expanded over the course of construction. These included power steering, power windows and central locking. More than 400,000 BMW 320i were once found on roads all over the world.