12,000-Watt Dual Fuel Generators: Peak vs Running Watts
“12,000 watt” on a generator listing usually means peak (starting) watts, not the output it can hold for hours. This guide compares the largest dual fuel generators in our generator comparison tool by both numbers, using manufacturer figures retrieved on 4 November 2026.
Peak watts vs running watts
Three models fall in or around the 12,000-watt class, depending on which number a listing uses.
- The Westinghouse WGen9500DF has 12,500 peak watts and 9,500 running watts on gasoline.
- The DuroMax XP13000EH has 13,000 peak watts and 10,500 running watts on gasoline.
- The Westinghouse WGen14500DF has 18,000 peak watts and 14,500 running watts on gasoline.
Running watts is the number to size against, because it is what the generator holds continuously. Our generator size calculator works from it.
Side-by-side
| Specification | WestinghouseWGen9500DFPortable | DuroMaxXP13000EHPortable | WestinghouseWGen14500DFPortable |
|---|---|---|---|
| Price and ownership cost | |||
| Listed price (USD, estimate) | $1,249.00Westinghouse MSRP | $1,299.00DuroMax listed price; shown against 1,699 USD compare-at price | $2,749.00Westinghouse MSRP |
| Price per rated watt (derived) | $0.13per watt, first fuel listed | $0.12per watt, first fuel listed | $0.19per watt, first fuel listed |
| Warranty | 3 years residential, 1 year commercial | 3 years | 3 years residential, 1 year commercial |
| Maintenance | Not stated | Not stated | Not stated |
| Oil capacity | Not stated | Not stated | Not stated |
| Power | |||
| Rated output by fuel |
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| Starting or surge watts | 12,500 W | 13,000 W | 18,000 W |
| Fuel types | Gasoline / Propane | Gasoline / Propane | Gasoline / Propane |
| Engine | Not stated | Not stated | Not stated |
| Displacement (cc) | 457 cc | 500 cc | 713 cc |
| Runtime, fuel use and running cost | |||
| Fuel tank (gal) | 6.6 gal | 8.3 gal | 10.5 gal |
| Runtime on a tank, as stated |
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| Fuel use, as stated | Not stated | Not stated | Not stated |
| Fuel per kWh (derived) | 0.174 galgasoline at 50% load, from tank size and stated runtime | 0.198 galgasoline at 50% load, from tank size and stated runtime | 0.161 galgasoline at 50% load, from tank size and stated runtime |
| Fuel cost per kWh at your price (derived) | |||
| Fuel cost per hour at that load (derived) | |||
| Size and comfort | |||
| Weight (lb) | 211 lb | 234 lb | 352 lb |
| Dimensions | Not stated | Not stated | Not stated |
| Noise (as stated) | 74 dBA | 74 dB | 74 dBA |
| Starting method | Electric, Remote, Recoil | Electric, Recoil | Electric, Remote |
| Features | |||
| Inverter output | No | No | No |
| Total harmonic distortion | Not stated | Not stated | ≤5% |
| Automatic voltage regulation (AVR) | Not stated | Yes | Not stated |
| CO sensor shutdown | No | Yes | Not stated |
| Transfer switch ready | Yes | Not stated | Not stated |
| Parallel capable | No | No | No |
| Outlets and connections | Two 5-20R duplex, L14-30R, 14-50R, transfer switch ready | Two 5-20R, L5-30R, L14-30R, 14-50R, 12V; GFCI | Two 5-20R GFCI, L5-30R, L14-30R, 14-50R, two USB |
| Fit | |||
| Suited to | Home backup, Construction and jobsite, Heavy duty | Home backup, Construction and jobsite, Heavy duty | Home backup, Construction and jobsite, Heavy duty |
| Also worth knowing | Transfer switch ready (ST switch) | AVR, CO sensor shutdown, GFCI outlets | V-twin engine; no recoil start |
| Honest take | |||
| Advantages |
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| Drawbacks |
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| Source | |||
| Where the figures come from | Westinghouse product pageRetrieved 2026-11-02 | DuroMax product pageRetrieved 2026-11-02 | Westinghouse product page (the older WGen12000DF address now shows this model)Retrieved 2026-11-04 |
How they differ
- Price per running watt: about $0.12 for the XP13000EH ($1,299), $0.13 for the WGen9500DF ($1,249 MSRP) and $0.19 for the WGen14500DF ($2,749 MSRP). These are our own divisions of listed prices.
- Propane output: 10,000 W (XP13000EH), 8,500 W (WGen9500DF) and 13,000 W (WGen14500DF).
- Weight: 211 lb, 234 lb and 352 lb.
- Engine: 457cc, 500cc and 713cc V-twin.
- Power quality: the WGen14500DF states THD of 5% or less. The other two do not state a THD figure, so protect sensitive electronics.
- Run time on a 6.6 to 10.5 gal tank: the XP13000EH states 17 hours at 25% load and 8 hours at 50% load on gasoline. The WGen9500DF states 12 hours at 25% and 8 hours at 50%. The WGen14500DF states 16 hours at 25% and 9 hours at 50%.
Models you may be looking for
Older articles, including earlier versions of this page, list the DuroMax XP12000EH and a Westinghouse WGen12000DF. Westinghouse’s WGen12000DF address now shows the WGen14500DF, with different ratings, and DuroMax lists the XP12000EH among its legacy models with conflicting run times on its page. We left both out of the comparison because we could not confirm their current specifications. Other brands that appear in “12000 watt” searches are not in our database yet, because we only add models we can verify from the maker.
Which to choose
| If you need | Look at |
|---|---|
| The lowest price per running watt | DuroMax XP13000EH |
| A transfer switch ready outlet and the lightest of the three | Westinghouse WGen9500DF |
| The highest output and a stated low THD | Westinghouse WGen14500DF |
What we could not verify
- Current availability. We have only the makers’ pages, not stock levels.
- Whether the XP13000EH and WGen14500DF are transfer switch ready. The tables list outlets, not the label.
- Reliability. We have no failure data.
Related guides
- Dual fuel generators for home backup
- Dual fuel generators compared
- Generator comparison by wattage
- Generator prices compared
Frequently asked questions
How many running watts is a 12,000 watt generator?
It varies by model. Among the models we track, a 12,500 peak listing runs at 9,500 W and a 13,000 peak listing runs at 10,500 W on gasoline.
Will a 12,000 watt generator run a whole house?
Not necessarily. Whole-house loads depend on air conditioning, electric heat and wells. Add up the running watts of what you need with the load calculator.
Are 12,000 watt generators dual fuel?
The three we track are. They run on gasoline or propane, with a lower rating on propane.
