The CAT 320D is a medium-class hydraulic excavator in the ~ 20–22 tonne range (depending on configuration). It is part of Caterpillar’s D-series lineup, designed to offer improved productivity, fuel efficiency, durability, operator comfort, and versatility compared to earlier models.The "D” in the model indicates its generation/series. The 320D features modern hydraulics, improved filtration, and better operator ergonomics. Various sub-variants include the standard 320D, 320D L (long undercarriage), and 320D3 (a later version) etc. The D series integrates features like the Cat ACERT™ engine technology, modular components, and serviceability improvements.