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The Evolution of Mid-Size Dozers in Earthmoving
Mid-size dozers have become the backbone of grading, site prep, and forestry work. Among the most recognized models in this class are the John Deere 700L and the Komatsu D51PX. Both machines represent decades of engineering refinement and brand-specific philosophies. John Deere, founded in 1837, has built its construction equipment legacy on operator-focused design and integrated technology. Komatsu, established in 1921 in Japan, is known for its durability, intelligent machine control, and global reach.
The 700L and D51PX are often compared by contractors looking for a balance between power, precision, and fuel efficiency. These machines are designed to operate in the 20,000–30,000 lb weight class, ideal for finish grading, slope work, and moderate clearing tasks.
Terminology Notes
The John Deere 700L is powered by a 6.8L PowerTech PVS engine producing approximately 135 horsepower. It uses a dual-path hydrostatic transmission, allowing independent control of each track for precise maneuvering. The Komatsu D51PX-24 features a 6.8L Komatsu engine delivering 131 horsepower, also paired with a hydrostatic drive system.
Both machines offer smooth, responsive control, but John Deere emphasizes operator customization through its EH controls and grade control compatibility. Komatsu counters with its IMC system, which automates blade movement based on terrain data.
Key specs:
John Deere’s 700L cab is designed with visibility and ergonomics in mind. The sloped hood and angled glass provide a clear view of the blade and surroundings. The seat is air-suspended, and controls are customizable through the monitor. Noise levels are reduced through improved insulation and engine mounting.
Komatsu’s D51PX cab is similarly refined, with a high-mounted seat and panoramic glass. The monitor displays real-time machine data and IMC feedback. Operators can adjust blade sensitivity and response curves depending on task.
One operator in Oregon noted that the 700L’s EH controls allowed him to fine-tune joystick response for slope work, while a contractor in Queensland praised the D51PX’s automatic blade control for reducing rework on long passes.
Blade Control and Grading Precision
Both machines use PAT blades, but their control systems differ. John Deere offers grade control compatibility with Topcon, Trimble, or Leica systems. The 700L can be fitted with SmartGrade, Deere’s integrated 3D grading solution.
Komatsu’s D51PX features factory-integrated IMC, which uses GNSS data to automate blade movement. The system adjusts blade height and angle in real time, reducing operator fatigue and improving finish quality.
In a side-by-side grading test on a subdivision site, the D51PX completed final passes with fewer corrections, while the 700L allowed more manual finesse for shaping complex contours.
Undercarriage and Ground Pressure
The LGP configurations of both machines are designed for soft or sensitive terrain. The 700L uses a sealed and lubricated track system with wide pads and heavy-duty rollers. Komatsu’s D51PX features a parallel link undercarriage with wide track frames and low center of gravity.
Ground pressure:
Maintenance and Serviceability
John Deere emphasizes ease of access with grouped service points and swing-out coolers. The 700L’s diagnostics are integrated into the monitor, and remote support is available through JDLink.
Komatsu offers centralized service ports and a tilting cab option for deeper access. The D51PX’s monitor provides maintenance reminders and fault codes. Komatsu’s KOMTRAX system allows fleet managers to track usage, location, and service intervals remotely.
Recommendations for Buyers and Fleet Managers
The John Deere 700L and Komatsu D51PX represent two philosophies in dozer design—one focused on operator customization and manual finesse, the other on automation and integrated intelligence. Both machines deliver exceptional performance in mid-size grading tasks, and the choice often comes down to jobsite demands and operator preference. Whether shaping slopes by hand or letting the machine handle the grade, these dozers prove that precision and power can coexist in a compact footprint.
Mid-size dozers have become the backbone of grading, site prep, and forestry work. Among the most recognized models in this class are the John Deere 700L and the Komatsu D51PX. Both machines represent decades of engineering refinement and brand-specific philosophies. John Deere, founded in 1837, has built its construction equipment legacy on operator-focused design and integrated technology. Komatsu, established in 1921 in Japan, is known for its durability, intelligent machine control, and global reach.
The 700L and D51PX are often compared by contractors looking for a balance between power, precision, and fuel efficiency. These machines are designed to operate in the 20,000–30,000 lb weight class, ideal for finish grading, slope work, and moderate clearing tasks.
Terminology Notes
- LGP (Low Ground Pressure): A track configuration with wider pads to reduce ground disturbance.
- PAT Blade (Power Angle Tilt): A blade that can be angled and tilted hydraulically for fine grading.
- Eco Mode: A fuel-saving setting that adjusts engine output based on load.
- IMC (Intelligent Machine Control): Komatsu’s integrated GPS grading system with automatic blade control.
The John Deere 700L is powered by a 6.8L PowerTech PVS engine producing approximately 135 horsepower. It uses a dual-path hydrostatic transmission, allowing independent control of each track for precise maneuvering. The Komatsu D51PX-24 features a 6.8L Komatsu engine delivering 131 horsepower, also paired with a hydrostatic drive system.
Both machines offer smooth, responsive control, but John Deere emphasizes operator customization through its EH controls and grade control compatibility. Komatsu counters with its IMC system, which automates blade movement based on terrain data.
Key specs:
- Horsepower: 700L – 135 HP / D51PX – 131 HP
- Operating weight: 700L – ~30,000 lbs / D51PX – ~30,800 lbs
- Transmission: Hydrostatic (both)
- Blade type: PAT (both)
John Deere’s 700L cab is designed with visibility and ergonomics in mind. The sloped hood and angled glass provide a clear view of the blade and surroundings. The seat is air-suspended, and controls are customizable through the monitor. Noise levels are reduced through improved insulation and engine mounting.
Komatsu’s D51PX cab is similarly refined, with a high-mounted seat and panoramic glass. The monitor displays real-time machine data and IMC feedback. Operators can adjust blade sensitivity and response curves depending on task.
One operator in Oregon noted that the 700L’s EH controls allowed him to fine-tune joystick response for slope work, while a contractor in Queensland praised the D51PX’s automatic blade control for reducing rework on long passes.
Blade Control and Grading Precision
Both machines use PAT blades, but their control systems differ. John Deere offers grade control compatibility with Topcon, Trimble, or Leica systems. The 700L can be fitted with SmartGrade, Deere’s integrated 3D grading solution.
Komatsu’s D51PX features factory-integrated IMC, which uses GNSS data to automate blade movement. The system adjusts blade height and angle in real time, reducing operator fatigue and improving finish quality.
In a side-by-side grading test on a subdivision site, the D51PX completed final passes with fewer corrections, while the 700L allowed more manual finesse for shaping complex contours.
Undercarriage and Ground Pressure
The LGP configurations of both machines are designed for soft or sensitive terrain. The 700L uses a sealed and lubricated track system with wide pads and heavy-duty rollers. Komatsu’s D51PX features a parallel link undercarriage with wide track frames and low center of gravity.
Ground pressure:
- 700L LGP: ~5.5 psi
- D51PX: ~5.3 psi
Maintenance and Serviceability
John Deere emphasizes ease of access with grouped service points and swing-out coolers. The 700L’s diagnostics are integrated into the monitor, and remote support is available through JDLink.
Komatsu offers centralized service ports and a tilting cab option for deeper access. The D51PX’s monitor provides maintenance reminders and fault codes. Komatsu’s KOMTRAX system allows fleet managers to track usage, location, and service intervals remotely.
Recommendations for Buyers and Fleet Managers
- For precision grading with manual control flexibility, the 700L is ideal
- For automated grading and reduced operator input, the D51PX excels
- Consider terrain type—both machines perform well in soft ground, but D51PX has a slight edge in flotation
- Evaluate dealer support and parts availability in your region
- Factor in resale value—both brands retain value well, but Komatsu’s IMC may appeal to tech-driven buyers
The John Deere 700L and Komatsu D51PX represent two philosophies in dozer design—one focused on operator customization and manual finesse, the other on automation and integrated intelligence. Both machines deliver exceptional performance in mid-size grading tasks, and the choice often comes down to jobsite demands and operator preference. Whether shaping slopes by hand or letting the machine handle the grade, these dozers prove that precision and power can coexist in a compact footprint.
