OffGrid Compare

Generac vs Cummins Generators

Last updated: March 2026

Generac sells more home generators than anyone. Cummins builds engines for semis, hospitals, and data centers: and happens to make a residential line that's quieter than anything else on the market.

Choose Generac if...

Choose Generac if you need a size above 20 kW, want the largest dealer network, or value having the most options.

Choose Cummins if...

Choose Cummins if noise is a top concern, you want built-in load management at no extra cost, or you need extreme cold weather performance down to -40°F.

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Head to Head

SpecGenerac 22kWCummins RS20A
Power (LP/NG)22 / 19.5 kW20 / 18 kW
Unit price$6,119$5,804
Installed cost$12,000–$17,000$11,000–$16,000
Noise67 dB65 dB
Load managementAdd-onBuilt-in (4 loads)
Footprint48" × 25"34" × 36"
Cold weatherStandard-40°F option

Noise

Cummins wins outright. 65 dB across all models in all modes. Generac matches at 14 and 18 kW (65 dB) but jumps to 67 dB at 22kW+. During a multi-day outage, that 2 dB gap is noticeable.

Selection

Generac offers seven sizes (10–28 kW). Cummins offers three (13, 17, 20). If you need more than 20 kW, Cummins doesn't have a residential air-cooled option.

Load Management

Cummins includes it on every model: 4 managed loads, no extra charge. Cummins claims the RS20A can start a 5-ton AC under full pre-load. Generac offers load management through specific transfer switch models but it's not built in.

Frequently Asked Questions

Is Generac or Cummins better for a home?
For homes under 3,000 sq ft where noise matters, Cummins is hard to beat. For homes needing 22kW+, or where dealer network and parts access matter most, Generac. The sizing requirement often makes the decision for you.
Which is quieter?
Cummins. 65 dB across all models in all modes. Generac matches at smaller sizes but jumps to 67 dB at 22kW+.
How much does each cost?
At 20–22kW: Cummins RS20A $11,000–$16,000 installed. Generac 22kW $12,000–$17,000. Cummins is ~$1,000 less with load management included.

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Sources & Citations

Claim / StatisticSource
Generac ~75% North American residential standby market shareinvesting.com(accessed 2025-03)
Generac dealer network (9,200+)generac.com(accessed 2025-03)
Generac owner reviews (1.6/5 from 130+ reviews)pissedconsumer.com(accessed 2025-03)
Generac 22/24kW alternator issues (reported, class action status unverified)topclassactions.com(accessed 2025-03)
Cummins QuietConnect specificationscummins.com(accessed 2025-03)
PissedConsumer generator brand reviewspissedconsumer.com(accessed 2025-03)
ConsumerAffairs generator reviewsconsumeraffairs.com(accessed 2025-03)
U.S. Energy Information Administration (fuel costs)eia.gov(accessed 2025-03)

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