John Deere 672G vs. Komatsu GD655-6: Visibility-First Engineering Against Mechanical Simplicity

23 hours ago

7 min read

We've now covered how CAT's 140 stacks up against both John Deere's 672G and Komatsu's GD655-6 -- which means the last side of the triangle is Deere against Komatsu directly, a comparison that's genuinely never been written up anywhere on this blog before, and rarely gets a real spec-by-spec treatment anywhere else either. Deere and Komatsu approach grader design from almost opposite starting points: one chases operator sightline and a staged technology ladder, the other chases mechanical simplicity and low cost of ownership. Both are legitimate strategies, and the right one depends entirely on what kind of grading work actually fills your schedule.

The Core Machines

John Deere's 672G runs a PowerTech PSS engine in the roughly 200-to-225-gross-horsepower class with a 14-foot standard moldboard, positioned toward the larger end of the mid-size grader bracket. Komatsu's GD655-6 runs its SAA6D107E engine in a somewhat lower horsepower range with a 12-to-14-foot moldboard depending on configuration -- so this comparison, like the others in this series, isn't a perfectly even horsepower match. Deere's 672G is built to move more material per pass; Komatsu's GD655-6 is built to do finer, more controlled work with less machine to maintain.

Deere's Sightline-First Cab

Deere's grader cab design centers on keeping the operator's eyeline as close to the cutting edge as the machine's layout allows, including a repositionable seat that lets the operator slide toward the side glass to watch the blade directly rather than estimating position from a mirror. On finish-grading passes where blade drift of even an inch can fail a proof-roll and cost a re-grade, that sightline advantage shows up directly in production rate and rework avoidance -- not a comfort feature, a real efficiency feature.

Deere also offers SmartGrade as a staged technology ladder from EZ Grade through full 3D GPS control, letting a contractor buy into grade-control technology incrementally rather than all at once. We've covered

how John Deere's SmartGrade tiers actually work in detail elsewhere on this blog if GPS grade control is part of your decision between these two machines.

Komatsu's Mechanical-Simplicity Case

Komatsu's GD655-6 takes the opposite philosophy: fewer electronically-mediated functions, a circle drive and blade-control linkage built around mechanical straightforwardness, and an engine and hydraulic tune that has built Komatsu a genuine reputation for fuel economy in this class. For an owner-operator who does some of their own maintenance, or a fleet working in a region with a thinner Komatsu dealer bench, that simplicity reduces the number of things that can go wrong in a way only a factory technician can fix, and it reduces fuel cost per hour on long grading days.

Dealer Network and Parts Reality

John Deere's dealer network is one of the deepest in North America across its full equipment line, and that extends to grader parts and service availability in regions where Komatsu's presence is thinner. That's a real, practical consideration independent of either machine's engineering merits: a grader down for a week waiting on a part costs more in lost production than almost any spec-sheet advantage recovers. Contractors working in regions with strong Komatsu dealer coverage -- which does exist in many markets, just less universally than Deere's -- won't feel this gap the same way a contractor in a thinner-coverage region would.

Who Should Be Cross-Shopping These Two

County and municipal road-maintenance contractors doing finish-grading work where blade accuracy directly affects whether a section passes inspection are the clearest fit for Deere's sightline-first approach. Aggregate operations, quarries, and land-development contractors who need a grader that's cheap to run and simple to keep in service, and who have the in-house capability to handle routine maintenance themselves, are the clearer fit for Komatsu's approach. Neither buyer is wrong -- they're solving for different constraints.

A grader that sits on a jobsite every week of the season almost always makes more financial sense to own than to rent repeatedly -- the math on cumulative rental rates versus a financed purchase tips toward ownership fast once a machine becomes a weekly-use tool rather than an occasional one.

Operator Training and the Learning Curve

There's an underappreciated cost to switching grader brands that rarely makes it into a spec comparison: operator retraining. A seasoned grader operator who has spent years running one brand's circle controls, pedal layout, and seat-slide ergonomics does not transfer that muscle memory instantly to a different manufacturer's cab, and a grader is one of the least forgiving pieces of heavy equipment to learn on a live jobsite, since a blade dragging an inch too deep on a finish pass can mean redoing an entire section of road. A contractor switching from an all-Deere operator roster to a Komatsu machine, or the other way around, should budget real time for operators to get comfortable before expecting full production rates, and that retraining cost is worth weighing against whatever price or spec advantage pushed the brand switch in the first place. Fleets that stick with one brand across their grader purchases, even when a competitor's newer model looks appealing on paper, are often making a quieter but genuinely sound decision to protect operator proficiency rather than chase marginal spec gains.

Scarifier and Ripper Attachments on Both Machines

Deere and Komatsu both offer a front scarifier and rear ripper as factory or dealer-fit options on their respective graders, and the practical decision here has less to do with brand engineering and more to do with what you're actually tearing up before the blade gets to it. A road-maintenance crew reclaiming an old, hard-packed gravel surface wants a scarifier mounted ahead of the moldboard to break the crust before grading; a contractor working tougher, rockier subgrade sometimes prefers a rear ripper's added breakout leverage, accepting the trade-off of reduced forward visibility to the freshly ripped material. Neither Deere nor Komatsu holds a clear mechanical edge on these attachments -- both mount to a conventional drawbar -- so this decision usually comes down to dealer stocking and lead time rather than engineering, and it's worth confirming availability before finalizing either purchase order.

A Real Scenario: A Municipal Subdivision-Street Rebuild

A contractor awarded a multi-block subdivision street rebuild -- cutting out failed base material, re-grading to spec, and prepping for new asphalt -- runs a grader through a tight, inspection-driven schedule where every pass has to hold grade tolerance the municipality's engineer will actually check. That's precisely the kind of finish-sensitive work where Deere's sightline-focused cab earns its keep, since passing proof-roll inspection on the first attempt rather than the third saves real calendar days on a contract that's almost always bonded against a completion date. If that same contractor is instead running a smaller crew with tighter equipment-cost margins and values simplicity and fuel economy over blade-sightline refinement, Komatsu's GD655-6 does the same fundamental job at a lower day-to-day operating cost, just with a bit more reliance on operator skill to hold the same tolerance without the cab's sightline advantage doing some of that work for them.

Resale and Trade-In Considerations

John Deere's dealer network and overall equipment sales volume give a used Deere grader a somewhat broader buyer pool at resale or trade-in time than a used Komatsu grader typically sees, simply as a function of how many contractors are actively shopping each brand at any given moment. That's not a knock on Komatsu's build quality, which holds up well by any honest measure -- it's a reflection of market depth rather than machine quality. A contractor planning to trade equipment on a fairly regular cycle, say every five to seven years, should weigh that resale liquidity alongside the machine's day-to-day fit for their work, since a faster, more predictable resale process has real value when it's time to upgrade.

Tandem and Circle Maintenance Over the Machine's Life

Both brands build their grader tandems and circles for field-replaceable wear components rather than requiring a full assembly swap when a drive gear or wear shoe wears down, which keeps long-term maintenance cost on either machine within a broadly similar range. Where the two diverge is in how many generations of design history each tandem carries: Komatsu's mechanical approach tends to change less generation over generation, which simplifies parts interchange across an older and a newer Komatsu grader in the same fleet, while Deere's more actively revised G-series tandems bring newer engineering at the cost of a narrower interchange window between machine years. A fleet planning to run graders of mixed ages side by side for a decade or more should weigh that interchange question directly with their dealer before standardizing on either brand.

Telematics and Fleet Monitoring

Both John Deere and Komatsu offer factory telematics on their grader lineups -- Deere through JDLink and Komatsu through its own fleet-monitoring platform -- giving a fleet manager remote visibility into hours, location, fault codes, and idle time without walking out to the machine. For a contractor running a handful of graders across multiple road-maintenance contracts spread over a county or region, that remote visibility genuinely changes how maintenance gets scheduled: instead of reacting to a breakdown call from the field, a fleet manager can see a developing fault code days in advance and schedule service before the grader actually goes down mid-contract. Deere's JDLink integrates directly with the same operations center a Deere-heavy fleet already uses for other equipment, which is a real convenience for an operation standardized on Deere across excavators, dozers, and graders alike. Komatsu's telematics platform offers comparable functionality and integrates just as well across a Komatsu-standardized fleet, so this isn't a case of one brand's technology being ahead of the other -- it's a case of which platform your existing fleet already reports into.

Fleets running a genuinely mixed brand lineup should also ask whether their telematics data can feed into a single third-party dashboard rather than juggling two separate manufacturer logins, since most fleet-management software today supports pulling data from multiple OEM platforms into one view -- a detail that matters more as a fleet grows past a handful of machines.

Financing Your Next Motor Grader

BFC arranges equipment financing and leasing for motor graders structured around how your grading work actually runs through the year, not a flat generic term. Seasonal road-maintenance contracts and aggregate operations with uneven cash flow both benefit from a payment schedule built around the real business rather than a one-size plan. Our

application process evaluates your whole business picture, which matters for contractors whose revenue is tied to seasonal or contract-based work rather than steady monthly billing.

Building out a larger site-development or road-maintenance fleet alongside a new grader? Our

construction equipment financing guide covers dozers, compactors, and wheel loaders for the rest of the lineup.