The Airman SDG45 delivers 36 kW of prime power (45 kVA) from an Isuzu 4LE2X engine, stepping up from the SDG40 into a larger enclosure with 80.5 gallons of onboard fuel for 28.75-hour runtime at full load. The unit produces switchable single and three-phase output from 120V through 480V.
At 3,337 lbs operating weight, the SDG45 remains towable and compact enough for urban construction sites while providing the power needed for mid-size commercial loads. Standard 110% fluid containment and Tier 4 Final compliance meet California environmental and emissions requirements.
The SDG45 sits at the inflection point in Airman's portable lineup where the enclosure steps up from the compact 67" x 31" frame shared by the SDG25 and SDG40 to a larger 74.8" x 38.2" platform. This larger enclosure accommodates the additional cooling capacity required by the 36 kW prime rating and provides improved serviceability — wider access panels make oil changes and filter swaps faster in the field. If your loads consistently run between 25 kW and 35 kW, the SDG45 operates efficiently in that range without the stress of running a smaller unit near its ceiling. For loads that peak above 40 kW, step up to the SDG65.
We deploy the SDG45 frequently on commercial construction projects throughout Silicon Valley and the East Bay — tenant improvement work in Sunnyvale and Mountain View office parks, restaurant build-outs in downtown San Jose, and retail fit-outs in Walnut Creek and Pleasanton. The 36 kW prime rating is the sweet spot for powering temporary lighting, tool circuits, and small HVAC equipment simultaneously during the rough-in phase of construction.
The Isuzu 4LE2X engine in the SDG45 shares its architecture with the proven 4LE2T in the SDG25 but with additional displacement to support the higher output. Field reliability is excellent — we see very few unscheduled service events on this model. The most common maintenance items are fuel filter replacements (especially on units that sit between jobs) and battery conditioning. We recommend keeping the fuel tank topped off during idle periods to minimize condensation, and using a quality float charger between deployments.
Engineering specifications
Physical
Length
74.8 in
Width
38.2 in
Height
61.4 in
Dry weight
2,954 lb
Wet weight
3,337 lb
Fuel system & runtime
Integral fuel tank
80.5 gal
Request a quote
Get pricing & lead time on the Airman SDG45
Tell us about the application — kW, voltage, application, install timeline — and we'll respond within one business day with budgetary pricing, lead time, and any sizing notes.
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
38.2 hours(1.6 days)
Fuel consumption ≈ 2.11 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 Airman SDG45 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
Clogging from contaminated or stale diesel causes hard starting and power loss — replace at 500-hour intervals or sooner if fuel quality is suspect
500+
minor
Starting battery
Capacity degradation during extended storage without a maintainer — test under load at every service visit and replace proactively at 36 months
4,380+
minor
Coolant hoses
Weeping at clamp points from thermal cycling — inspect during every oil change and replace at first sign of swelling or seepage
5,000+
minor
Frequently Asked Questions
What is the standby rating of the Airman SDG45?
The Airman SDG45 delivers 39 kW standby / 36 kW prime at 60 Hz (45 kVA). It provides switchable single and three-phase output across voltages from 120/240V through 277V and 416/480V.
What engine does the Airman SDG45 use?
The SDG45 is powered by an Isuzu 4LE2X — a turbocharged diesel running at 1,800 RPM with EPA Tier 4 Final compliance. The 4LE2X shares its architecture with the proven 4LE2T in the SDG25 but with additional displacement to support the higher 36 kW prime output.
What is Airman's warranty claim rate?
Airman generators are built by Hokuetsu Industries in Japan and carry a documented 0.001% warranty claim rate — the lowest in the portable generator industry. This figure reflects the precision manufacturing standards applied to every unit built at the Hokuetsu facility.
What are the service intervals for the SDG45?
The Isuzu 4LE2X engine in the SDG45 requires oil and filter changes every 500 hours or 12 months (whichever comes first), air filter replacement at 500 hours, fuel filter replacement at 500 hours, and is rated for major overhaul at 20,000 hours.
Is the SDG45 EPA compliant?
Yes. The Airman SDG45 meets EPA Tier 4 Final emissions standards through its Isuzu 4LE2X turbocharged engine. The unit is California-compliant for construction, event, and temporary power applications.
What fluid containment does the SDG45 have?
All Airman generators, including the SDG45, feature 110% fluid containment as standard. The integrated drip tray holds more than the total volume of all engine fluids, eliminating the need for separate secondary containment on California job sites.
Who services Airman generators in Northern California?
OnPoint Generators is the authorized Airman service provider for Northern California. We stock parts, perform warranty service, and offer maintenance contracts for the full Airman SDG lineup including the SDG45.
Similar models
Airman
Airman SDG45SV V-Pump
Industry-leading 0.001% warranty claim rate with 110% fluid containment standard — no separate secondary containment needed on CA sites.
39 kW standby · Diesel · Liquid-cooled
Rental fleets and construction sites requiring ultra-reliability and environmental compliance.
45 kVA (36 kW prime) portable diesel generator with integrated VFD for motor starting and dewatering.
Tier 4 Final3-phaseconstructionrental-fleet
Airman
Airman SDG40
0.001% warranty claim rate, 110% fluid containment standard, 37-hr runtime in the same footprint as the SDG25 — maximum power density with lowest total cost of ownership.
30 kW standby · Diesel · Liquid-cooled
Mid-range 29 kW portable for construction sites needing more power without a larger footprint. Ideal for commercial TI projects, utility work, and multi-day unattended temporary power.
28.6 kW prime diesel portable generator. Kubota-powered with 37-hour runtime at full load and 110% fluid containment standard.
Tier 4 Final3-phaseconstructionrental-fleet
Airman
Airman SDG65
0.001% warranty claim rate, 110% fluid containment standard, 28.5-hr runtime at 51 kW — bridges the gap between compact towables and large trailer units with premium Isuzu reliability.
55 kW standby · Diesel · Liquid-cooled
Mid-size 51 kW portable for commercial construction, emergency standby, and event power where loads exceed 36 kW but a full-size 100 kW trailer is unnecessary.
51 kW prime diesel portable generator. Isuzu 4JJ1X engine with 28.5-hour runtime, 111-gallon tank, and 110% fluid containment.
Tier 4 Final3-phaseconstructionrental-fleet
Need service or parts for the Airman SDG45?
We service every major OEM and stock genuine parts for the most common models.
