CAT D3 vs. Komatsu D39EX-24: The Small-Dozer Class Compared

Oct 5

6 min read

Below the D4 and D51EX-24 sits an even smaller dozer class that does a different kind of work entirely — residential lot clearing, utility right-of-way maintenance, small acreage work, and the kind of tight-access grading where a bigger machine simply can't fit. CAT's D3 and Komatsu's D39EX-24 are the current small-dozer entries from each brand in this class, and like their larger siblings one size class up, they land remarkably close together on the numbers.

Spec-for-Spec

CAT D3: 104 net hp, operating weight 20,321 to 21,150 lb depending on configuration, 91-inch standard track gauge with an optional 30-inch LGP (low ground pressure) track available. Part of CAT's redesigned D1/D2/D3 Next Generation small-dozer lineup.
Komatsu D39EX-24: 105 net hp at 2,200 rpm (78 kW), operating weight 21,891 lb (9,930 kg), blade capacity 2.89 yd³ (2.21 m³), ground pressure 5.24 psi standard-shoe configuration, Tier 4 Final compliant.

One horsepower apart again, and under 1,000 lb apart on operating weight — this is the second dozer weight class in a row where CAT and Komatsu have landed on almost identical output. That's not a coincidence; it reflects where the market has settled on "how much machine" a small-dozer buyer actually needs, and both manufacturers are building to that same target.

The "EX" and "PX" Naming Convention Actually Matters

Komatsu's small-dozer naming isn't arbitrary. The "EX" in D39EX-24 denotes the standard-gauge, general-purpose track configuration — narrower tracks, better transport width, and a tighter turning footprint for confined work. The sibling "PX" variant (D39PX-24) runs a wider track gauge for better flotation and stability on soft or sloped ground, at the cost of some maneuverability in tight spaces. We've covered that specific internal Komatsu choice in depth in our D39PX-24 vs. D39EX-24 comparison — worth reading alongside this one if you're trying to decide not just CAT-vs-Komatsu but which Komatsu variant fits your ground conditions.

CAT addresses the same tradeoff differently: rather than two separate model numbers, the D3's standard 91-inch track and optional 30-inch LGP track are configuration choices within the same base model. Functionally similar outcome, different ordering process — a CAT dealer builds the LGP configuration to order, while a Komatsu buyer picks between two distinct model numbers from the start.

Who Actually Buys a Dozer This Small

This class shows up most often with residential and light-commercial site developers clearing and grading individual lots rather than whole subdivisions, utility and pipeline crews maintaining rights-of-way where a bigger machine can't maneuver, land-clearing operations working smaller acreage parcels, and municipal or county road departments doing shoulder work and small-scale grading where trailering a bigger dozer isn't worth the hassle. It's also a common first dozer for a startup grading or excavation company that needs to prove out a dozer line of work before committing to a bigger, more expensive machine.

Transport Economics at This Size

Both machines, at right around 20,000-22,000 lb, sit comfortably within the capacity of a standard tandem-axle equipment trailer pulled by a one-ton dually — no need for a specialized low-boy or a CDL-rated combination in most states for occasional moves. That accessibility is a real part of the appeal at this size class: a two- or three-person outfit can own and move either the D3 or D39EX-24 without adding a dedicated truck-and-trailer investment on top of the dozer itself.

Rent-vs-Own for a Startup Grading Company

A small dozer is often the first piece of real earthmoving equipment a new grading or land-clearing business buys, and the rent-vs-own math at this price point is especially stark for a startup still building a customer base. Renting a small dozer by the day or week for scattered jobs adds up fast against a monthly loan payment on a machine the business keeps using and keeps building equity in — especially once job volume reaches even two or three dozer jobs a month.

BFC provides equipment financing for small dozers like the CAT D3 and Komatsu D39EX-24 to startups with no established credit history as well as existing fleets adding a smaller machine. Deposit requirements scale with credit strength rather than a flat formula — apply here to see real terms for your business.

Section 179 for a First-Time Equipment Purchase

A small dozer purchase is a strong candidate for Section 179 depreciation treatment in its first year of service, which can meaningfully reduce a profitable business's tax liability in the year it's placed into use. The exact deduction depends on total equipment spend and taxable income for the year — confirm specifics with your tax professional — but for a startup weighing whether to finance the D3 or D39EX-24 now versus waiting, placing the machine in service before year-end can let that year's tax benefit apply while the dozer is already earning on jobsites.

The Bottom Line

At 104 and 105 net hp respectively, the CAT D3 and Komatsu D39EX-24 are close enough on paper that the decision comes down to configuration flexibility, dealer relationship, and what the rest of your fleet already runs. CAT's single-model-with-options approach and Komatsu's separate EX/PX model numbers solve the same soft-ground tradeoff two different ways — neither is wrong, and either one beats renting once your job count justifies owning.

See BFC's full dozer equipment financing options for either machine, new or used.

Blade Capacity and What It Actually Means on a Small Lot

Komatsu doesn't publish a standard blade capacity figure for the D39EX-24 as prominently as some of its larger dozers, but third-party spec databases consistently cite the 2.89 yd³ figure we've used here, derived from the straight-blade configuration most commonly ordered on this model in the US market. CAT's D3, meanwhile, is typically specified with a 6-way power-angle-tilt (PAT) blade as the common configuration for this class, which trades some raw capacity for the ability to angle and tilt the blade without leaving the seat — a genuinely useful feature on residential lot work where you're constantly adjusting for drainage grade, curb cuts, and property-line obstacles rather than pushing straight material in a long pass. That's a configuration difference worth asking your dealer about directly, because the base spec sheet numbers don't always reflect which blade type ships as standard versus optional in your specific market.

Operator Comfort and Visibility at This Size

Small dozers spend a disproportionate amount of their working life in tight, obstacle-heavy environments compared to their larger siblings — residential lots with existing trees and structures, utility easements with buried infrastructure markers, and road shoulders with traffic running alongside. That makes cab visibility and operator comfort a bigger practical factor at this size than raw power. Both CAT and Komatsu have invested in redesigned operator stations for their current small-dozer generations — CAT's Next Generation D1/D2/D3 platform specifically touted improved sightlines and a redesigned seat and control layout when it launched, while Komatsu's -24 generation dozers carry forward the same cab ergonomics improvements the brand has rolled out across its broader small-to-mid dozer range. Neither brand has published a direct side-by-side comparison of the two cabs, so this is genuinely a "sit in both before you buy" decision if operator comfort over a full shift matters to your crew.

Financing a First Dozer vs. Expanding a Fleet

There's a meaningful difference in how financing conversations go for a startup buying its first dozer versus an established grading company adding a second or third machine in this class. A brand-new business with no equipment-financing history yet typically faces a higher deposit requirement and more scrutiny on personal credit and business plan — not because the lender doubts the equipment's value, but because there's less operating history to underwrite against. An established company adding a D3 or D39EX-24 as a second machine, by contrast, usually has existing equipment, a payment track record, and real revenue history that makes the financing conversation faster and the terms more favorable. Either way, structuring the loan against the dozer itself as collateral — rather than relying purely on general business credit — is often what makes financing possible at all for a newer operation.

What to Ask Before You Commit to Either Machine

Blade configuration: confirm whether a straight blade or 6-way PAT blade ships as standard on the specific unit you're quoted — this changes both price and capability.
Local parts stocking: ask your dealer directly what undercarriage and hydraulic wear parts they keep on the shelf locally versus what requires a special order.
Track gauge needs: if your sites run consistently soft or sloped, ask about the wider-gauge PX option on the Komatsu side or the LGP configuration on CAT's — don't default to standard gauge just because it's the base price point.
Trade-in and resale: ask your dealer what current used values look like for the outgoing generation (D6K2 for CAT, the prior D39EX dash-number for Komatsu) to get a sense of how well either machine is likely to hold value.

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