CAT 320 vs 320B vs 320C vs 320D vs 320GC vs 320GX: Years, Engines, and Which to Buy

Last updated: November 13, 2026 Sellers love one label: 20 ton Cat digger . Buyers get a stack of names that are not the same machine—CAT 320, 320B, 320BL, 320C, 320CL, 320D, 320 GC, 320 GX. Same size class. Different years, engines, and repair habits. This guide lines up the series the way export buyers actually talk: approximate production years, operating weight, typical engine, and whether you are dealing with mechanical direct injection or electronic control. For the buying checklist and landing path, see how to buy a 20-ton CAT excavator . How to read L, BL, and CL L / BL / CL usually means a longer (and often heavier) undercarriage setup—more track on the ground, better stability on soft ground or when digging deep. It is not a separate engine family by itself. A 320CL is still a C-series machine; a 320BL is still a B-series machine. Always confirm the plate letters before you compare two WhatsApp quotes. Master comparison (approximate trade ranges) Years overlap by plant and market. Listing “year” can be wrong. Weight moves with boom, stick, shoes, and counterweight. Treat the table as a starting map—then verify serial / PIN. Model Typical years (approx.) Weight (approx.) Engine (typical) Injection (buyer talk) Main strength 320 (early) mid–late 1990s ~19–21 t early 320-class diesel Mechanical DI Simple iron; clean units are scarce 320B / 320BL ~1998–2001 ~19.4–21 t Cat 3066T Mechanical DI Field-repair friendly; square-body recognition 320C / 320CL ~2001–2006 ~20–22.5 t (CL heavier) Cat 3066 TA / ATAAC Mechanical DI Export workhorse; strong parts velocity 320D (D / DL / D2…) ~2006–2014+ ~20–22 t C6.4 ACERT; D2 often C7.1 Mostly electronic; confirm serial Modern hydraulics/cab; needs fuel discipline 320 GC Next Gen (~2017+) ~20–22 t Cat C4.4 Electronic DI Lower owning-cost “GC” proposition 320 GX ~2021+ (value line) ~19.8–20 t Cat C4.4 Electronic DI Fast payback / lower entry vs GC or performance line Direct injection vs electronic injection (plain English) Ads often mix two different ideas: Direct injection (DI / 直喷): where fuel is sprayed—into the combustion chamber. Electronic injection (电喷): how delivery is controlled—ECU and sensors instead of only a mechanical pump rack. They are not a beauty contest. Many later machines are both: electronic control and direct injection. Older 3066-era 320B/C machines are typically mechanical DI —simpler field habit. C6.4 / C4.4 platforms are usually electronically controlled ; they can be more efficient when fuel is clean, and more expensive when water, dirt, or skipped filters show up. If a seller only writes “electronic DI” with no engine model, treat it as a slogan until the plate and engine family are proven. 320 / early class Advantage: basic layout, fewer electronics, known Cat badge in the 20-ton band. Buy when: you find a documented unit and your workshop likes older iron. Skip when: identity is vague, undercarriage is finished, or the seller invents a late production year for an early plate. 320B / 320BL Advantage: Cat 3066T mechanical DI era; workshops that “adjust by ear” often prefer it. Square body is easy to recognize in yards. Typical years: roughly 1998–2001 in most trade talk. A listing that says “2007 320B” is usually marketing fiction—check the plate. Buy when: diesel quality is uneven and you want simple fuel systems. Skip when: rails are gone or the pump is weak—cheap B-series iron with no track life is not cheap. 320C / 320CL Advantage: still one of the most searched used 20-ton Cats for export. 3066 TA / ATAAC keeps mechanical DI habits while adding better cooling and a stronger day-to-day feel than many B units. 320CL brings the longer undercarriage many African and Asia buyers want. Typical years: about 2001–2006. Huge second-hand supply from Japan, Europe, the U.S., and China. Buy when: you want parts velocity, resale recognition, and a mid-budget working machine. For price bands on 320CL specifically, see the used CAT 320CL global price guide . Skip...