Dual Fuel vs Tri Fuel Generators: Which Should You Buy? (2026)

Dual fuel vs tri fuel generators

The difference is simple: a dual fuel generator runs on two fuels — gasoline and liquid propane (LP) — while a tri fuel generator adds a third, natural gas (NG) piped from your home's utility line. Everything else — the engine, the outlets, the wattage — works the same way. This guide covers which one is right for home backup, an RV, or a jobsite.

How each one works

Both types burn fuel to spin an engine that turns an alternator, producing electricity. You select the active fuel with a valve or dial before starting. Dual fuel gives you gasoline for convenience and propane for clean, long-storage backup. Tri fuel adds a natural-gas hookup, so during a long outage you can run straight off your home's gas supply and never refuel.

Why the third fuel (natural gas) matters

Natural gas is the headline reason to choose tri fuel. If your home has a natural-gas line, a tri fuel generator can run essentially indefinitely during an outage — no gas cans, no swapping propane tanks. The trade-offs: you need that NG connection (and often a proper hookup done to code), and generators typically produce somewhat less peak power on natural gas than on gasoline, because NG is less energy-dense.

Which should you choose?

• Choose dual fuel if you want flexibility and portability — gasoline when you're out with an RV or on a jobsite, propane for clean fuel that stores for years. It's the most popular choice and usually the lower price.
• Choose tri fuel if home backup is the priority and you have a natural-gas line. Unlimited runtime on utility gas during a multi-day outage is the payoff.

Many buyers land on dual fuel for all-around use, and step up to tri fuel specifically for whole-home resilience. Browse both in our dual fuel generators and full generators collections.

What they share

Fuel options don't change the fundamentals, so still compare: running vs. peak (surge) watts, whether it's an inverter model (cleaner power for electronics, quieter, more fuel-efficient), 120V-only vs. 120/240V, electric or remote start, CO safety shutoff, and transfer-switch readiness for backing up your panel. For quiet, battery-based backup that pairs well with a generator, see our portable power stations.

Frequently asked questions

What is the difference between a dual fuel and a tri fuel generator?
Dual fuel runs on gasoline and propane; tri fuel adds natural gas from your home's utility line.

Are tri-fuel generators worth it?
They're worth it if you have a natural-gas line and want unlimited backup runtime during long outages. Without an NG hookup, the third fuel adds cost you won't use.

Can a portable generator run on natural gas?
Yes — a tri fuel portable generator can, once connected to your natural-gas supply, usually through a proper regulator and hookup.

Do you lose power running on propane or natural gas?
Slightly. Most units make peak power on gasoline and a bit less on propane, and a bit less again on natural gas, because each is progressively less energy-dense.

Is dual fuel or tri fuel better for an RV?
Dual fuel — you won't have a natural-gas line on the road, so the third fuel adds no benefit there.

This article is general information, not electrical or professional advice. Connecting a generator to a natural-gas line or your home's electrical panel must be done with the correct equipment by a qualified professional, per the manufacturer's manual and local codes. Never run any generator indoors or in an enclosed space.