How Long Will a Standby Generator Run During an Extended Power Outage?

Standby generators can run indefinitely if they have fuel. Your generator's runtime depends primarily on your fuel source and proper maintenance practices.

Fuel Sources and Runtime Expectations

Natural Gas (NG) Generators

Unlimited runtime – Connected directly to your utility's natural gas line
No fuel tank required – Continuous supply eliminates refueling concerns
Most common in metropolitan areas – Ideal for homeowners with natural gas service

Liquid Propane (LP) and Diesel Generators

Limited by tank capacity – Runtime depends on fuel storage size
Common in rural areas – Best option where natural gas is unavailable
Requires fuel monitoring – Tank levels must be checked regularly

Diesel Generator Tank Options

Diesel generators typically come with fuel tanks designed for different durations:

24-hour tanks (standard)
48-hour tanks (optional)
72-hour tanks (optional)

If you use LP or diesel fuel, establish a relationship with a reliable refueling service. During extended outages, stay in contact with your provider to schedule regular tank refills.

Maintenance During Extended Outages

Recommended Shutdown Schedule

Shut down air-cooled generators every 36-48 hours to:

Allow the engine to cool properly
Check and adjust oil levels
Prevent engine wear and overheating

Important: This is especially critical for air-cooled generators with engines running at 3600 RPM. Liquid-cooled generators running at 1800 RPM can endure week-long power outages lasting 7-10 days.

Oil Level Checks

When checking oil during shutdowns:

Wait for the engine to cool
Check levels carefully
Add oil as needed
Avoid overfilling – This can cause serious engine problems

Choosing the Right Generator Engine

1800 RPM Engines (Premium Choice)

Best for extended outages

Run cooler and quieter
Use less oil
More fuel efficient
Superior reliability
Higher initial cost
Ideal for absolute reliability needs

3600 RPM Engines (Standard Choice)

Best for short-term outages

Lower purchase price
Reliable performance
Higher oil consumption
Runs hotter during extended use
Good for occasional backup power

Why Choose Diesel Generators?

Diesel generators are widely considered the most reliable option available. Trusted manufacturers like Cummins built their reputation on dependable diesel engines with over 100-years of product innovation and engineering.

Advantages:

Exceptional reliability
Proven long-term performance
Durable construction

Considerations:

Higher upfront cost
Requires fuel tank monitoring
Need for refueling service relationship

Find Your Perfect Generator at Buckeye Power Systems

We're an authorized dealer for Cummins Power Generation – the industry leader in quality and reliability.

Our Product Selection

Cummins Air-Cooled Generators – Perfect for essential circuits and smaller homes

Cummins Liquid-Cooled NG/LP Generators – Whole house coverage for larger properties

Cummins Diesel Home Generators – Maximum reliability for critical applications

All generators are in stock and ready to ship.

Get Expert Guidance Today

Our trained representatives can help you:

Select the right generator size for your needs
Choose the best fuel type for your location
Understand maintenance requirements
Compare models and features

Contact Us

Phone: 901-379-8097

Hours: Monday - Friday, 9:00 AM - 5:00 PM CDT

Don't wait until the next power outage. Call Buckeye Power Systems today and ensure your home or business has reliable backup power when you need it most.