Komatsu D39PX-24 vs. D39EX-24: Wide Gauge or Standard Gauge for Your Small Dozer

Komatsu's small dozer line splits into two letter codes that confuse a lot of first-time buyers: PX and EX. Both the D39PX-24 and D39EX-24 share the same 105-horsepower engine and the same core PLUS undercarriage philosophy, but the differences between them, in track gauge, ground pressure, operating weight, and blade capacity, decide which one actually belongs on your jobsite.

The Shared Platform

Both machines run the same 105 HP engine at 2,200 rpm, both use Komatsu's hydrostatic transmission (HST) with electronic controls for automatic shifting and variable speed selection, and both come with a power angle tilt (PAT) blade featuring adjustable pitch. Neither one is a stripped-down version of the other; they're genuinely parallel machines built on the same engineering base, aimed at different ground conditions.

Where They Actually Differ

The D39PX-24 carries an operating weight of 22,817 lbs and a blade capacity of 3.14 cubic yards. The D39EX-24 comes in lighter at 21,891 lbs with a 2.89 cubic yard blade. That roughly 900-lb weight difference and larger blade on the PX model is consistent with Komatsu's PX naming convention across its whole dozer line: PX models run a wider track gauge for lower ground pressure, which is why they carry more structure and a bigger blade, while EX models run the standard gauge built for firmer ground and general-purpose dozing.

In practice, that means the D39PX-24 is the machine to reach for on soft, wet, or loose ground, like fresh fill, wetland-adjacent sites, or loose sand, where a narrower-gauge machine would sink in or struggle for traction. The D39EX-24 is the better fit on firmer, more established ground, like compacted pads, gravel lots, or general grading on soil that's already stable, where the extra width and weight of the PX variant isn't buying you anything and the EX's slightly lighter, more maneuverable frame is the better tool.

What Replaced What

The -24 generation replaces the prior D39PX-23 and D39EX-23 models. The D39PX-23 ran the same 105 HP engine at a lighter 21,671.5-lb operating weight, meaning the -24 update added roughly 1,145 lbs of structure while keeping horsepower flat, consistent with the reinforced, more durable builds Komatsu has rolled out across this dozer generation's refresh. That's not a flashy headline change, but a heavier, more reinforced frame at the same power output generally means a longer working life before structural wear becomes a problem, which matters more to an owner keeping a machine for years than to a renter who hands it back after a week.

Who Should Buy Which

Land-clearing and site-development contractors working raw, ungraded land with soft or inconsistent ground conditions should lean toward the D39PX-24; the wider gauge and lower ground pressure are built for exactly that unpredictability. General contractors and grading subs working established sites, pads, and roadways with firmer, more consistent ground get more value from the D39EX-24's lighter, more maneuverable frame. Demolition contractors clearing debris-strewn sites, where ground conditions can shift block by block, often find the PX's extra stability worth the added weight even on sites that aren't uniformly soft.

The Rent-vs-Own Math on a Specialist Small Dozer

A small dozer sized and configured for your specific ground conditions is exactly the kind of machine that's hit-or-miss at a rental yard, since most yards stock one configuration, not both the PX and EX variants side by side. If your work consistently runs on soft ground and the yard's only available small dozer that week is a standard-gauge EX-style machine, you're either fighting the wrong tool or waiting on availability. Owning the specific configuration your ground conditions actually call for means that fight never happens.

BFC finances Komatsu's full dozer lineup, including both the D39PX-24 and D39EX-24, for startups and established contractors nationwide, on good credit or bad. You don't need to pay off one machine before financing the next piece of equipment your fleet needs, whether that's a second small dozer configured differently or something else entirely.

For more on Komatsu's dozer lineup, see our spotlight on the Komatsu D61PXi-25's IMC 3.0 upgrade, our explainer on KOMTRAX telematics and resale value, and our look at the 40-year history of Komatsu's Chattanooga plant.

Finance the Right Small Dozer for Your Ground

Ready to add a D39PX-24, D39EX-24, or any other Komatsu dozer to your fleet? Visit our home page to learn more, or go straight to our equipment financing application to get started. Looking to buy or sell equipment outright? Browse our equipment for sale inventory. And for more coverage like this, subscribe to our blog.