Generac · Portable generator · GP18000EFI COsense 50ST
GP18000EFI COsense 50ST delivers up to 18,000 running watts and 22,500 starting watts from a portable gasoline system.
Infographic gallery
18,000W rated output
The comparison uses Generac’s published rated and peak, surge, or maximum output figures.
Energy source
Gasoline
Published runtime guidance
9 hours at 50% load on the primary listed fuel
442.8 lb
Listed weight
39.5 × 30.9 × 36.5 in
Dimensions
Charging or integration
Fueling and starting per Generac instructions; manual transfer equipment sold separately
Backup transfer
Not an automatic standby system; approved manual transfer equipment is required for home connection
Noise
No official dBA figure listed on the model page
Official product gallery
The current official image set for GP18000EFI COsense 50ST includes product views, connection diagrams, feature explanations, and compatible system configurations where Generac publishes them.
Complete specifications
These pages retain Generac's model-specific output, charging, battery, port, continuity, dimensions, environmental, engine, fuel, app-control, and warranty fields where published.
System capability
GP18000EFI COsense 50ST delivers up to 18,000 running watts and 22,500 starting watts from a portable gasoline system.
Power delivery
From emergency home backup to DIY projects to the jobsite, the Generac GP18000EFI portable generator provides high wattage, dependable portable power.
Safety and controls
Equipped with an 816cc engine with Electronic Fuel Injection, the GP18000EFI delivers power efficiently, providing up to 9 hours of runtime at 50% load.
Runtime and fueling
TruePower™ Technology safely powers sensitive electronics, appliances and tools while onboard COsense® Technology provides powerful protection against hazardous carbon monoxide.
Portability detail
The GP18000EFI also features electric start (battery included), low-oil shutdown protection, circuit breaker protected outlets and an hour meter with maintenance resets.
Connection options
The included never-flat wheel kit and available lifting eye accessory make transportation easy around the home or jobsite.
Ownership note
Featuring COsense® Technology: STOPS.
Additional manufacturer note
Powerful protection against hazardous carbon monoxide.
Best-fit uses
Standout features
Use the independent calculator before choosing a battery system or generator.
Find My Generator score
Best for specific needs
Compared with 144 high output portable generators in the current catalog.
Running and peak output versus the class
Longest published runtime figure
Lower weight scores higher
Single-fuel operation
Output or stored energy per listed dollar
Class comparison
A number is more useful with context. Each row shows this model beside its class median and translates the difference into a percentile.
Running output
Higher than 98% of its class
Peak output
Higher than 97% of its class
Published runtime
Longer than 16% of its class
Product weight
Lighter than 4% of its class
How the score works: Scores use published specs and are relative to comparable products in this catalog. Missing specs are excluded and remaining weights are normalized. Runtime is the longest manufacturer-published figure and may use a different load or fuel than another model.
Ownership resources
Start with the exact Generac GP18000EFI COsense 50ST model or item number. Accessory families can look alike while using different connectors, electrical limits, engines, or mounting points.
Compatible accessories
Use a correctly rated cord or professionally selected inlet connection for the intended load.
This model’s published information references parallel operation. Use the manufacturer’s matching kit and pairing rules.
Model-matched filters, spark plugs, batteries, oil supplies, and service parts support scheduled maintenance.
A fitted storage cover protects a cooled, stored generator. A running shelter must be designed for generator operation.
Compatibility note: Links lead to manufacturer or official retailer resources. Confirm the full model or item number, connector type, voltage, amperage, and published compatibility list before buying. Installation involving a home panel, inlet, transfer switch, or fuel plumbing should be handled as required by local code.