What is the standby power rating of the Doosan G25?

The Doosan G25 delivers 22 kW standby and 20 kW prime power. It is the entry-level model in the Doosan G-Series portable generator lineup and is also sold as the Bobcat PG25.

What engine does the Doosan G25 use?

The G25 is powered by a Doosan D18 1.8-liter inline-3 diesel engine running at 1,800 RPM. The D18 is a naturally aspirated engine with no turbocharger and no DPF — EPA Tier 4 Final compliance is achieved through DOC-only aftertreatment, keeping maintenance simple.

What are the service intervals for the Doosan G25?

Oil changes are due every 250 hours or 12 months, whichever comes first. Air filter and fuel filter replacement intervals are 500 hours. Major engine overhaul is specified at 20,000 hours under normal operating conditions.

Is the Doosan G25 EPA compliant?

Yes. The G25 is EPA Tier 4 Final compliant, meeting current U.S. emissions requirements. The Doosan D18 achieves compliance through DOC aftertreatment without requiring a DPF or DEF — no regeneration cycles to manage.

How does Doosan compare to Cummins or CAT at the 25 kVA class?

At the 20-25 kW range, Doosan uses its own proprietary D18 engine rather than Cummins or CAT powerplants. The D18's simple naturally aspirated design means fewer failure points than turbocharged competitors. Doosan typically prices 15-30% below CAT portable units at comparable specifications.

What control panel does the Doosan G25 use?

The G25 is equipped with Doosan's standard digital control panel featuring auto-start, manual start, fault monitoring, and runtime tracking. The panel is integrated into the CoolBox enclosure door for protected access in outdoor deployment conditions.

Doosan / Bobcat · G-Series

Doosan G25

Name: Doosan G25
Brand: Doosan / Bobcat
Availability: PreOrder

22 kW standby / 20 kW prime · Diesel · Liquid-cooled

20 kW prime diesel portable generator. Doosan D18-powered with 63 dBA operation and 25-hour runtime at full load.

Standby power: 22 kW / 20 kW prime
Voltage options: 120/240V, 208V, 480V
Frequency / Phase: 60 Hz · 1/3-phase
Engine: Doosan D18 · 1.8L
EPA / Emissions: Tier 4 Final

Commercialrental-fleettemporary-power

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Overview#

The Doosan G25 is the entry point in Doosan's portable diesel generator lineup, delivering 20 kW of prime power from a compact Doosan D18 engine. At 63 dBA at full load, the G25 competes with the quietest units in the 25 kVA class while typically pricing 15-30% below premium brands like MQ Power and Airman.

The G25 runs 25 hours at full load and features Doosan's CoolBox acoustically-treated enclosure with integrated high-capacity fuel tank and environmental containment. Now sold as the Bobcat PG25, the unit is mechanically identical regardless of badge.

CoolBox enclosure and Doosan D18 engine#

The G25's CoolBox enclosure provides full sound attenuation at 63 dBA — competitive with MQ Power WhisperWatt units at this power level. The enclosure integrates the fuel tank into the skid baseframe with environmental containment, meeting jobsite spill-prevention requirements without a separate secondary containment tray.

The Doosan D18 is a 1.8-liter 3-cylinder diesel — a compact, mechanically simple engine with no turbocharger and no DPF. Tier 4 Final compliance is achieved through DOC aftertreatment only, which keeps maintenance straightforward. Oil change intervals are 250 hours, and the engine's simplicity means fewer failure points than turbocharged alternatives at this power level.

Our service experience#

OnPoint services Doosan portable generators across Northern California. The D18 engine in the G25 is one of the simpler powerplants in the portable generator market — no turbo, no DPF, just a naturally aspirated diesel with DOC aftertreatment. Fuel filters are the most common service item at 500-hour intervals. For rental fleet operators, the G25's lower acquisition cost compared to MQ Power or Airman means faster ROI on utilization, and the CoolBox enclosure holds up well to jobsite conditions.

Engineering specifications

Physical

Length: 130.5 in
Width: 72.8 in
Height: 76.6 in
Wet weight: 3,140 lb

Acoustic

Sound @ 7m, full load: 63 dBA
Enclosure: Sound-attenuated

Fuel system & runtime

Integral fuel tank: 46.7 gal

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Estimate runtime for the Doosan G25

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

39.3 hours(1.6 days)

Fuel consumption ≈ 1.19 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 Doosan G25 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.

Oil & filter: Every 250 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	Restricted flow, hard starting, power loss under load	500+	minor
Battery	Failed to start or slow cranking after extended storage	4,380+	minor
Coolant hoses	Weeping at clamp connections, slow coolant loss	5,000+	minor

Frequently Asked Questions

What is the standby power rating of the Doosan G25?: The Doosan G25 delivers 22 kW standby and 20 kW prime power. It is the entry-level model in the Doosan G-Series portable generator lineup and is also sold as the Bobcat PG25.
What engine does the Doosan G25 use?: The G25 is powered by a Doosan D18 1.8-liter inline-3 diesel engine running at 1,800 RPM. The D18 is a naturally aspirated engine with no turbocharger and no DPF — EPA Tier 4 Final compliance is achieved through DOC-only aftertreatment, keeping maintenance simple.
What are the service intervals for the Doosan G25?: Oil changes are due every 250 hours or 12 months, whichever comes first. Air filter and fuel filter replacement intervals are 500 hours. Major engine overhaul is specified at 20,000 hours under normal operating conditions.
Is the Doosan G25 EPA compliant?: Yes. The G25 is EPA Tier 4 Final compliant, meeting current U.S. emissions requirements. The Doosan D18 achieves compliance through DOC aftertreatment without requiring a DPF or DEF — no regeneration cycles to manage.
How does Doosan compare to Cummins or CAT at the 25 kVA class?: At the 20-25 kW range, Doosan uses its own proprietary D18 engine rather than Cummins or CAT powerplants. The D18's simple naturally aspirated design means fewer failure points than turbocharged competitors. Doosan typically prices 15-30% below CAT portable units at comparable specifications.
What control panel does the Doosan G25 use?: The G25 is equipped with Doosan's standard digital control panel featuring auto-start, manual start, fault monitoring, and runtime tracking. The panel is integrated into the CoolBox enclosure door for protected access in outdoor deployment conditions.
Who services Doosan generators in Northern California?: OnPoint Generators services Doosan G-Series portable generators across the Bay Area and Northern California. The D18 engine in the G25 is one of the simpler powerplants in the portable generator market, and we stock common consumables for rapid service turnaround.

More in the G-Series

Cummins and Doosan engines in a purpose-built portable enclosure — 22 to 500 kW at a competitive price.

View all 13models in this series →

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