Stack / P4500i

Cummins Onan P4500i

Updated · 5 Nov 2026 · Sheet checked · 5 Nov 2026

It depends — 3,700 W running, 4,500 W peak, 120 V only; TT-30R plus 5-20R duplex; electric, remote and recoil start; 98 lb; EPA-only, not CARB

For an RV on a 30 A cord, or a fridge, freezer and window AC on extension cords: 3,700 W running. The 4,500 W in the name is peak watts.

Exact part A074Z436: the EPA-only P4500i, "Not for sale in California" on its Cummins sheet. Not the EPA/CARB A058U955, and not the dual-fuel P4500iDF.

What it is

Wheeled gasoline inverter. Cummins Onan 224 cc OHV engine; push-button, fob remote (99 ft) and recoil start; battery included.

Fuel: 3.4 gal steel tank, E10 or less.

Outlets: one 120 V 30 A TT-30R, one 120 V 20 A 5-20R duplex, two 5 V USB, and parallel outlets for the Cummins 50 A parallel kit (A058M290, manual). No 240 V. The 30.8 A on the sheet is rated running current at 120 V, not a receptacle rating.

Grounding: neutral floating. Low-oil shutdown; THD ≤3%.

CO: no CO shutoff listed (sheet, manual). The manual says operate outdoors only, far from doors, windows and vents, and install battery or battery-backup CO detectors in living areas.

Noise "as low as 52 dBA" (sheet; no distance). Dry weight 98 lb. Warranty 3-year limited residential.

US$1,078.65 at Cummins' store (checked 4 Nov 2026).

Links: no affiliate.

What it will actually run

Running watts first: 3,700 W. Surge second: 4,500 W, motor starts only.

Derating (manual): about 3.5% per 1,000 ft and 1% per 10 °F above 60 °F; above 2,000 ft, fit the altitude kit.

Runtime: the A074Z436 EPA sheet contradicts itself — front page 18 h at 25%, table 15.6 h at 25% / 10 h at 50%. Product page and CARB sheet also say 18 h. Plan from 15.6 h.

Outage Stack math (not manufacturer): 25% load is about 925 W; 72 hours at that load burns about 16 gal of gasoline, about 4.6 tankfuls.

Will run (Outage Stack estimates)

a fridge (150–400 W running, 600–1,200 W starting, size table), a freezer (700 W running, 2,200 W starting, manual's wattage chart), lights and phones (50–150 W) and one 8–10k BTU window AC (800–1,200 W running, 1,800–3,000 W starting): about 2,450 W running
Start motors one at a time (manual)
A microwave (1,000–1,500 W) fits with the AC off

Skip or measure first

Any 240 V well pump: a 1/2–3/4 hp pump needs 2,000–4,000 W starting, and the unit has no 240 V. A 120 V pump: measure yours against 4,500 W peak
A CPAP: the 30–60 W fits, but the manual says never use the generator to power medical support equipment

Home connection: the manual says a generator supplying building wiring "must be installed by a qualified electrician and connected to a transfer switch as a separately derived system in accordance with NFPA 70." The sheet lists "Manual transfer switch ready: No".

Specs that matter

Running: 3,700 W (30.8 A running at 120 V, sheet)
Peak: 4,500 W (37.5 A starting at 120 V, sheet), not continuous
120 V, 60 Hz; parallels with P4500i, P4500iDF or P2500i
Neutral floating; 104 °F max ambient (manual); EPA only
24.5 × 18.3 × 20.5 in, 98 lb dry

Who should skip it

You live in California or want CARB: this part is not for sale there; ask for A058U955.
You need 240 V for a well pump or transfer-switch inlet: look at the 120/240 V Champion 201175.
You want propane: Cummins sells a dual-fuel P4500iDF; Outage Stack hasn't reviewed it.
You only need a fridge and lights: the live Honda EU2200i lists 1,800 W running.

Verdict

It depends. Buy it for a 30 A RV or a cord-run fridge, freezer and window AC with fob remote start: 3,700 W running, clean power, 98 lb. Skip it if you need 240 V, a transfer-switch inlet, propane or California sale. Plan from 3,700 W, never 4,500 W.

Sources: Cummins — P4500i EPA sheet A074Z436 (watts, amps, outlets, runtime table, weight, emissions) · Cummins — P4500i operator manual A062R852 Issue 3 (grounding, transfer switch, CO, medical, derating, wattage chart, parallel kit) · Cummins — P4500i product page (EPA/CARB sheets, 18 h claim) · Cummins — portable generators page (15.6 h, P4500iDF) · Cummins store — A074Z436 US$1,078.65 (checked 4 Nov 2026; US page did not render a price on 5 Nov) · Outage Stack — size table and live peers Champion 201175, Honda EU2200i. Last checked: 2026-11-05.

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