What engine does the DE40I4 use?

The DE40I4 uses an Isuzu 4LE2X 2.2-liter four-cylinder turbocharged diesel engine with electronic common rail injection (Bosch CP4.1). The 4LE2X is Isuzu's Tier 4 Final industrial engine, widely supported through Isuzu's global dealer network.

What makes Winco different from Generac or Kohler?

Winco generators use non-proprietary Isuzu 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?

PowerGen services Winco DE units throughout the Bay Area and Northern California. The Isuzu engine and Stamford alternator are non-proprietary — parts come through standard diesel supply channels, not through a dedicated Winco dealer network.

Winco · DE Series

Winco DE40I4

Name: Winco DE40I4
Brand: Winco
Availability: PreOrder

36 kW standby / 32.4 kW prime · Diesel · Liquid-cooled

36 kW standby diesel generator with Isuzu 4LE2X turbocharged engine. Tier 4 Final. Largest DE series unit. US-made.

Standby power: 36 kW / 32.4 kW prime
Voltage options: 120/240V, 277/480V
Frequency / Phase: 60 Hz · 1/3-phase
Engine: Isuzu 4LE2X · 2.2L
EPA / Emissions: Tier 4 Final

Commercial

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Overview#

The Winco DE40I4 is a 36 kW standby / 32.4 kW prime diesel generator powered by an Isuzu 4LE2X 2.2-liter four-cylinder 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 (120/208V, 120/240V, 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 36 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.

The American Manufacturing Advantage#

Winco has assembled generators in Le Center, Minnesota since 1927 with US labor and components. The DE40I4 uses an Isuzu 4LE2X 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 36 kW. The Isuzu 4LE2X engine is serviced through Isuzu's global industrial dealer network and standard diesel parts distributors.

Service & Maintenance#

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.

Our Service Experience#

PowerGen services Winco DE units throughout the Bay Area and Northern California. The Isuzu 4LE2X 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 36 kW.

Engineering specifications

Acoustic

Enclosure: Open

Documents & downloads

Spec sheets & manuals

Spec sheet (datasheet)

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Estimate runtime for the Winco DE40I4

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

Estimate runtime on this tank

Generator size

Fuel

Fuel tank capacity

gal

Load

Override full-load GPH (optional)

GPH

Estimated runtime

102.9 hours(4.3 days)

Fuel consumption ≈ 1.94 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 36 kW standby / 32.4 kW prime (single-phase, 1.0 PF). It is the largest unit in Winco's DE open-frame diesel series, available in single-phase (120/240V) and three-phase (120/208V, 120/240V, 277/480V).
What engine does the DE40I4 use?: The DE40I4 uses an Isuzu 4LE2X 2.2-liter four-cylinder turbocharged diesel engine with electronic common rail injection (Bosch CP4.1). The 4LE2X is Isuzu's Tier 4 Final industrial engine, widely supported through Isuzu's global dealer network.
What makes Winco different from Generac or Kohler?: Winco generators use non-proprietary Isuzu 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?: PowerGen services Winco DE units throughout the Bay Area and Northern California. The Isuzu engine and Stamford alternator are non-proprietary — parts come through standard diesel supply channels, not through a dedicated Winco dealer network.

Compatible equipment

Engine

Isuzu 4LE2XEngines

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Open-frame USA-made diesel standby for indoor generator rooms — 20 to 40 kW on Isuzu and FPT engines.

View all 3models in this series →

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