The Allis-Chalmers D15, introduced in 1960, was a versatile and powerful tractor designed to serve a wide range of farming needs. The D15 came in two distinct series: Series I and Series II, each with notable improvements and features. Series I, produced from 1960 to 1962, featured a four-cylinder engine with options for both gas and diesel fuel. The gas engine delivered about 41 horsepower, while the diesel version provided around 38 horsepower. This range of power made the D15 suitable for a variety of tasks, from plowing and cultivating to mowing and hauling.
In 1963, Allis-Chalmers introduced Series II, which remained in production until 1968. This series included several enhancements, such as an increased compression ratio in the gas engine, boosting its output to approximately 46 horsepower, and improved hydraulics for better performance with attachments. The diesel engine also saw improvements in efficiency and durability. Both series featured a refined Power Director transmission, which allowed for smoother shifting and greater control over different speeds and operations. The Allis-Chalmers D15, with its combination of power, versatility, and innovative features, became a popular choice among farmers and remains a favorite among vintage tractor enthusiasts today.