Kohler · REOZ Series (Diesel Commercial Standby)

Kohler 48REOZK4

47 kW standby / 42 kW prime · Diesel · Liquid-cooled

48 kW Tier 4 Final diesel commercial standby generator. Kohler-powered diesel with EPA Tier 4 Final emissions compliance for commercial and institutional applications.

Kohler Kohler 48REOZK4 generator — specifications and details
Standby power
47 kW / 42 kW prime
Voltage options
120/208V, 277/480V, 120/240V
Frequency / Phase
60 Hz · 1/3-phase
Engine
Kohler KDI 3404 TCR · 3.4L
EPA / Emissions
Tier 4 Final
CommercialHealthcareGovernment
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Overview#

The Kohler 48REOZK4 is a 48-kilowatt EPA Tier 4 Final diesel commercial standby generator powered by a Kohler diesel engine at 1800 RPM. It achieves Tier 4 Final compliance through cooled exhaust gas recirculation (EGR) and a diesel oxidation catalyst (DOC). The unit features a durable sound-attenuating steel housing rated at 69 dB(A) at 7 meters, integrated environmental containment, a Fast-Response permanent magnet excitation system, and a lockable battery disconnect switch.

Our service experience#

OnPoint services Tier 4 Final Kohler diesel generators across Northern California. The 48REOZK4 is a popular mid-range choice for commercial buildings in air quality districts that require Tier 4 certification, and shares the REOZK enclosure platform with the 30 and 40 kW models.

Engineering specifications

Physical

Length
98.6 in
Width
44.1 in
Height
74.6 in
Wet weight
4,385 lb

Acoustic

Sound @ 7m, full load
69 dBA
Enclosure
Sound-attenuated

Fuel system & runtime

Integral fuel tank
102 gal
Fuel use @ full load
3.8 GPH
Fuel use @ 75% load
2.9 GPH
Fuel use @ 50% load
2 GPH

Photos

Kohler 48REOZK4 — product photo

Documents & downloads

Spec sheets & manuals

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Configure your Kohler 48REOZK4

Lock the enclosure, fuel system, transfer switch, and add-ons — we'll confirm pricing, availability, and lead time within one business day. Prefer a free-form quote? That option is still here.

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Estimate runtime for the Kohler 48REOZK4

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

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Estimated runtime

34.8 hours(1.4 days)

Fuel consumption ≈ 2.93 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 Kohler 48REOZK4 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.

Oil & filter
Every 250 hours or 12 months
Coolant change
Every 2000 hours
Air filter
Every 500 hours
Fuel filter
Every 250 hours
Major overhaul
≈ 8,000 hours
Load bank test
Every 12 months

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.

ComponentSymptomTypical hoursSeverity
DPF (Diesel Particulate Filter)Regen warning, back-pressure fault, power derate4,380+moderate
Fuel quality / degradationInjector fouling, hard starting, reduced power output4,380+moderate
Battery (starting)Slow crank, failed exercise, low voltage alarm8,760+minor

Frequently Asked Questions

What engine is in the Kohler 48REOZK4?
The 48REOZK4 uses a Kohler diesel engine rated at 1800 RPM with EPA Tier 4 Final emissions certification via cooled EGR and diesel oxidation catalyst.
What is the sound level of the 48REOZK4?
Per Kohler specifications, the 48REOZK4 is rated at 69 dB(A) at 7 meters at full load with the sound-attenuating steel housing.
Does the 48REOZK4 include environmental containment?
Yes. The unit includes a 125% environmental containment basin for oil/coolant and a 110% secondary fuel containment tank with UL 142 listed subbase fuel tank for 24-hour minimum runtime at prime rating.

Compatible equipment

Transfer switches

More in the REOZ Series (Diesel Commercial Standby)

Kohler's diesel commercial standby series — 10 to 510 kW, John Deere and Kohler engines, built for life-safety loads.

View all 33models in this series →

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