Generac · model 8917
Portable Generator · Gasoline
~$4,399approx. list price
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18,000 W running, 22,500 W surge — sustains the whole home with central air tier.
Best forOwners of large homes who want whole-house portable power through a 50-amp transfer switch and are willing to refuel it by hand.
The biggest portable Generac sells, built for the buyer who wants to run a whole house, central air included, from a 50-amp transfer switch without buying a standby unit. The 816cc engine uses electronic fuel injection, which owners value for easier cold starts and less carburetor trouble after a season in storage, and the 14-50R receptacle plus 22,500 watts of starting capacity can start a 4 to 5 ton AC. THD under 5% means the output is clean enough for electronics. It also weighs about 443 lbs, burns through its 14.2 gallon tank in about nine hours at half load, and has no published noise figure, so expect it to be loud next to a neighbor's fence. At $4,399 it costs about the same as a Guardian 14kW before the transfer switch, so the real question is whether you will wheel it out and refuel it in a storm. The 50-state version is the one on the maker's current page.
From the spec sheet
18,000 W running, 22,500 W surge·816cc EFI engine, THD under 5%·14-50R plus L14-30R outlets
At a glance
At a glance
Head to head
Portable Generator · Gasoline
6,500 W / 8,125 W surge · up to furnace blower, sump pump or a window AC
Best for Homeowners with a 30-amp transfer inlet who want a mid-size gasoline generator with CO shutdown and a national parts network.
Portable Generator · Gasoline
8,000 W / 10,000 W surge · up to well pump or a small central AC
Best for Storm-prep buyers who want maximum conventional watts from a big-box store the week before landfall.
Home Standby Generator · NG/LP · 61 dB
10,000 W · up to well pump or a small central AC
Best for Smaller homes that want automatic backup for essential circuits without paying whole-house prices.