Should You Choose the Hitachi EX100M-1 or the EX120-5

[MikePhua]

Hitachi’s Excavator Legacy and Market Reach
Hitachi Construction Machinery, founded in 1970, has built a global reputation for durable, efficient excavators. The EX series, especially the EX100 and EX120 models, became staples in Southeast Asia, Africa, and Latin America during the 1980s and 1990s. These machines were known for their mechanical simplicity, robust undercarriages, and long service life in harsh conditions. By the mid-1990s, Hitachi began integrating electronic controls, marking a shift toward more sophisticated diagnostics and fuel efficiency.
Terminology Notes

• High Clearance Machine: An excavator with elevated undercarriage and boom geometry, allowing better navigation over stumps, rocks, or uneven terrain.
  
• -5Z Variant: A sub-model of the EX120-5 that omits computerized engine and hydraulic controls, favored for reliability in remote areas.
  
• Electronic Control System: A set of sensors and modules that manage engine performance, hydraulic flow, and diagnostics.
  
• Dipper Arm: The second segment of the boom, connecting the main boom to the bucket.
  

EX100M-1 Overview

• Year Introduced: 1988
  
• Operating Weight: Approximately 12,300 kg
  
• Design: High-clearance frame, nearly as large as a modern EX200
  
• Engine: Mechanical diesel, no electronic control
  
• Strengths:
  • Excellent for forestry and swamp work
    
  • Simple hydraulics and engine layout
    
  • Easy to repair in the field
    
• Limitations:
  

• Older parts may be harder to source
  
• Lower fuel efficiency
  
• No onboard diagnostics
  

Operators in Malaysia and Indonesia often praise the EX100M-1 for its ability to climb over logs and debris without bottoming out. One contractor used it for six years in peatland reclamation, noting that it outperformed newer machines in terms of uptime and ease of repair.
EX120-5 Overview

• Year Introduced: 1996
  
• Operating Weight: Approximately 11,800 kg
  
• Engine Power: Higher than EX100M-1, with improved torque curve
  
• Design: Compact frame, lower clearance
  
• Strengths:
  • Better fuel economy
    
  • Smoother hydraulic response
    
  • Available with electronic diagnostics
    
• Limitations:
  

• Electronic control systems can be problematic in humid or remote environments
  
• Requires specialized tools for troubleshooting
  
• Some variants (-5Z) lack computerization, preferred by mechanics
  

One operator shared that his EX120-5 performed flawlessly in urban excavation but struggled in jungle terrain due to lower clearance. He eventually swapped it for a -5Z model, which eliminated the electronic control module and simplified maintenance.
Comparison Summary

• Terrain Adaptability: EX100M-1 wins in rough, forested, or swampy terrain.
  
• Fuel Efficiency: EX120-5 offers better consumption rates and smoother operation.
  
• Maintenance: EX100M-1 is easier to repair with basic tools; EX120-5 requires diagnostic equipment unless it’s a -5Z.
  
• Parts Availability: EX120-5 parts are more common in urban markets; EX100M-1 parts may require sourcing from older yards or Japan.
  

Recommendations Based on Use Case

• Forestry, Swamp, or Remote Work: Choose EX100M-1 for its clearance and mechanical simplicity.
  
• Urban, Grading, or Infrastructure Projects: Choose EX120-5 for fuel savings and hydraulic finesse.
  
• Mixed Use with Limited Support Access: Seek out the EX120-5Z variant to avoid electronic complications.
  

Conclusion
Choosing between the Hitachi EX100M-1 and EX120-5 depends on terrain, support infrastructure, and operator preference. The EX100M-1 is a mechanical workhorse built for rugged conditions, while the EX120-5 offers modern efficiency with a caveat—its electronics can be a liability in remote regions. For those who value simplicity and field serviceability, the EX100M-1 remains a timeless choice. For those working near service centers and needing precision, the EX120-5 delivers. Either way, Hitachi’s legacy ensures both machines will keep digging long after others retire.