The Winco DE40I4 is a 40 kW standby / 35 kW prime diesel generator powered by an FPT Industrial N45-family 4.5-liter turbocharged diesel engine with a Stamford alternator. It is the largest unit in Winco's DE open-frame diesel series. Available in single-phase (120/240V) and three-phase (277/480V) configurations, it serves mid-size commercial, agricultural, and institutional standby applications. EPA Tier 4 Final certified. 100% US-made in Le Center, Minnesota since 1927.
At 40 kW, the DE40I4 is the top of the DE line before stepping up to Winco's DR series. Its open-frame design is intended for indoor generator room installation, giving the installer full flexibility on ventilation, exhaust routing, and fuel supply configuration.
Winco has assembled generators in Le Center, Minnesota since 1927 with US labor and components. The DE40I4 uses an FPT Industrial N45 engine and a Stamford alternator — both non-proprietary components with global independent distribution networks. This is Winco's defining value: US-made standby power that is not dependent on a single OEM's parts supply chain.
For institutional customers — school districts, municipal utilities, federal contractors — with Buy American procurement mandates, the DE40I4 is a qualifying US-manufactured product at 40 kW. The FPT N45 engine is serviced through CNH Industrial's global network (Case IH, New Holland) and standard diesel parts distributors.
Oil and fuel filter changes every 500 hours or annually. EPA Tier 4 Final compliance means the engine includes modern emissions aftertreatment (DOC/DPF) that requires periodic maintenance — add this to the service schedule alongside standard consumables. Annual fuel filter changes are mandatory for standby units regardless of hours, as diesel degrades in storage.
The Stamford alternator requires standard brush, bearing, and insulation maintenance. Transfer switch contacts should be exercised weekly to prevent oxidation during standby. Major overhaul at 20,000 hours.
OnPoint Generators services Winco DE units throughout the Bay Area and Northern California. The FPT Industrial N45 and Stamford alternator components are non-proprietary — our technicians source parts through standard commercial diesel channels. For clients with Buy American requirements or a preference for US-made open-frame diesel standby with component independence, the DE40I4 is the top of Winco's DE line and a reliable choice at 40 kW.
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Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.
Estimate runtime on this tank
Estimated runtime
92.6 hours(3.9 days)
Fuel consumption ≈ 2.16 GPH at 75% load. Estimate based on industry-typical 1800 RPM standby curves (≈0.07 GPH/kW at full load). Actual consumption varies by engine, ambient temperature, fuel quality, and tuning.
Service intervals
Manufacturer-recommended intervals for the Winco DE40I4 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 500 hours or 12 months
Air filter
Every 500 hours
Fuel filter
Every 500 hours
Major overhaul
≈ 20,000 hours
Common failure modes
What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.
Component
Symptom
Typical hours
Severity
Fuel filter
Extended standby fuel degradation — change annually regardless of hours
500+
minor
Starting battery
Capacity loss in standby — float charge, test annually
4,380+
minor
Transfer switch contacts
Oxidation on standby generators — exercise weekly to maintain contact quality
8,760+
minor
Frequently Asked Questions
What is the standby kW rating of the DE40I4?
The DE40I4 is rated at 40 kW standby / 35 kW prime. It is the largest unit in Winco's DE open-frame diesel series, available in single-phase (120/240V) and three-phase (277/480V).
What engine does the DE40I4 use?
The DE40I4 uses an FPT Industrial N45-family 4.5-liter four-cylinder turbocharged diesel engine from CNH Industrial. The N45 is a widely deployed industrial platform used in Case IH and New Holland agricultural equipment worldwide.
What makes Winco different from Generac or Kohler?
Winco generators use non-proprietary FPT Industrial engines and Stamford alternators — both globally serviceable by any qualified diesel technician. Winco has manufactured 100% in Le Center, Minnesota since 1927. Generac and Kohler offer proprietary engines, connected monitoring, and denser dealer networks but with parts and service lock-in.
Is the DE40I4 EPA Tier 4 Final compliant?
Yes. The DE40I4 carries EPA Tier 4 Final certification, meeting current non-road diesel emissions standards for new installations.
Where are Winco generators made?
100% in Le Center, Minnesota. Winco (formerly Winpower) has operated at that US facility since 1927 — America's oldest generator manufacturer.
What are the service intervals for the DE40I4?
Oil and fuel filter changes every 500 hours or annually. Air filter inspection at 500 hours. Annual changes are mandatory for standby units where diesel degrades in storage. Major overhaul at 20,000 hours.
Who services Winco generators in Northern California?
OnPoint Generators services Winco DE units throughout the Bay Area and Northern California. The FPT Industrial engine and Stamford alternator are non-proprietary — parts come through standard diesel supply channels, not through a dedicated Winco dealer network.
More in the DE Series
Open-frame USA-made diesel standby for indoor generator rooms — 20 to 40 kW on Isuzu and FPT engines.
