Is the Caterpillar CT660 a Smart Investment for Heavy Hauling

[MikePhua]

Caterpillar’s Foray into On-Road Trucks
Caterpillar, long revered for its dominance in earthmoving and mining equipment, made a bold move in 2011 by entering the on-road vocational truck market with the CT660. This Class 8 truck was designed to serve dump, mixer, and heavy-haul applications, combining Caterpillar’s rugged reputation with a custom-built chassis and cab. The CT660 was assembled in partnership with Navistar, using the International PayStar platform as its base. Despite Caterpillar’s strong brand presence, the CT660 was discontinued in 2016 after a short production run, making it one of the company’s more controversial ventures.
Terminology Annotation

• Class 8 Truck: A heavy-duty truck classification for vehicles with a gross vehicle weight rating (GVWR) over 33,000 pounds.
  
• CT15 Engine: Caterpillar’s rebadged version of Navistar’s MaxxForce 15, a 15-liter diesel engine used in the CT660.
  
• EGR (Exhaust Gas Recirculation): An emissions control system that recirculates exhaust gases to reduce nitrogen oxide emissions.
  
• DPF (Diesel Particulate Filter): A device that captures soot from diesel exhaust, requiring periodic regeneration.
  

Engine and Emissions System Concerns
The CT660’s most debated feature is its CT15 engine, which was essentially a rebranded Navistar MaxxForce 15. While the engine block itself was structurally sound, the emissions system proved problematic. Instead of using DEF (Diesel Exhaust Fluid) like most competitors, the CT15 relied solely on EGR and a unique fuel-injection strategy to regenerate the DPF. This design led to frequent regeneration cycles, excessive fuel consumption, and reliability issues.
Operators reported:

• Frequent downtime due to clogged DPFs
  
• Inconsistent power delivery during regeneration
  
• High maintenance costs for EGR valves and coolers
  
• Limited dealer support for emissions-related repairs
  

These issues were compounded by the fact that Caterpillar exited the on-road engine market in 2010, leaving Navistar to handle engine development and support. The CT660’s emissions system became a liability, especially for fleets operating in urban or stop-and-go environments.
Chassis and Drivetrain Performance
Despite engine concerns, the CT660’s chassis was well-regarded. It featured:

• 14,000 lb front axle and 46,000 lb rear axles
  
• Eaton Fuller 18-speed manual or Allison automatic transmission options
  
• Steel cab construction with ergonomic interior layout
  
• Configurable wheelbase and frame options for vocational customization
  

The truck’s ride quality, visibility, and cab comfort were praised by drivers. For hauling end dumps, demolition trailers, or mixers, the CT660 offered solid mechanical performance—provided the engine and emissions system were functioning properly.
Anecdote from a Demolition Contractor
In 2015, a demolition company in Nevada purchased a CT660 to pull a high-side end dump. The truck was priced $45,000 below a comparable Kenworth T880, and came with a five-year bumper-to-bumper warranty. Initially, the truck performed well, but within 18 months, it spent over 40 days in the shop due to emissions faults. The dealer honored the warranty, but delays in parts and corporate approvals caused costly downtime. Eventually, the company sold the truck at auction and replaced it with a pre-emission 2002 Peterbilt 379 with a rebuilt N14 Cummins engine.
Resale Value and Market Position
Because Caterpillar discontinued the CT660 and exited the truck market, resale values have plummeted. Fleet buyers and dealers refer to the CT660 as an “orphan”—a vehicle with no future factory support. Auctions frequently list CT660s at steep discounts, and parts availability for emissions components can be limited.
Buyers considering a CT660 should factor in:

• Depreciation risk due to discontinued status
  
• Limited aftermarket support for CT15 engine
  
• Potential need for emissions system deletion (where legal)
  
• Bargain pricing compared to new vocational trucks
  

Recommendations for Prospective Buyers

• Avoid CT660s with high mileage unless emissions systems have been overhauled
  
• Consider pre-emission trucks (1999–2002) with mechanical engines for reliability
  
• If purchasing a CT660, negotiate dealer support guarantees and parts availability
  
• Use the truck in long-haul or rural applications to minimize regeneration cycles
  
• Keep diagnostic tools and spare sensors on hand for emissions troubleshooting
  

Preventative Maintenance Strategies

• Clean EGR coolers every 50,000 miles
  
• Monitor DPF backpressure and schedule manual regenerations
  
• Replace fuel filters every 15,000 miles to protect injectors
  
• Use high-quality oil to reduce soot buildup
  
• Inspect wiring harnesses for corrosion near the ECU and sensors
  

Conclusion
The Caterpillar CT660 is a vocational truck with a strong chassis and a troubled engine. While its mechanical components perform well under load, the emissions system—based on Navistar’s EGR-only design—has proven unreliable and costly to maintain. For buyers who prioritize upfront savings and can manage emissions-related risks, the CT660 may offer value. However, for long-term fleet reliability and resale strength, pre-emission or mainstream alternatives like Kenworth, Peterbilt, or Freightliner remain safer bets. Caterpillar’s brief experiment in the on-road truck market serves as a cautionary tale about brand extension and emissions technology missteps.