Last verified: October 1, 2026
Generac and Kohler (now sold under the Rehlko company name) are the two most common names in home standby generators. On paper their 26 kW models are close. Kohler delivers more power on natural gas; Generac has the bigger dealer and parts network. For most homeowners, which brand has a strong local dealer decides the matter.
26 kW models head to head
| Generac Guardian 26 kW | Kohler 26RCAL | |
|---|---|---|
| Output on propane | 26 kW | 26 kW |
| Output on natural gas | 22.5 kW | 24 kW |
| Natural gas use, ½ load | 188 cu ft/h | 180 cu ft/h |
| Natural gas use, full load | 333 cu ft/h | Not listed on product page |
| Propane use, ½ load | 75 cu ft/h (vapor) | 85 cu ft/h (vapor) |
| Sound, normal operation | 67 dB(A) at 23 ft | 67 dB(A) |
| Sound, weekly exercise | 57 dB(A) (low-speed Quiet-Test) | 56 dB(A) |
| Enclosure | Aluminum | Aluminum, rated for winds up to 181 mph |
| Standard warranty | 5-year limited | 5-year limited; dealer service coverage up to 200 miles |
| Starting price | Set by dealers | MSRP from $8,515 (unit) |
Sources: Generac 26 kW Guardian spec sheet; Kohler 26RCAL product page. Propane use is shown as vapor cubic feet per hour; one gallon of liquid propane is roughly 36 cubic feet of vapor, so 75–85 cu ft/h is about 2.1–2.3 gallons per hour.
Where Kohler has the edge
- Natural gas output. 24 kW versus 22.5 kW on natural gas. If your load calculation lands between those numbers, Kohler’s 26 kW may cover a house that Generac’s cannot without load management.
- Slightly lower natural gas use at half load (180 vs 188 cu ft/h, per the manufacturers).
- Higher wind rating on the enclosure, a consideration in hurricane zones.
- Dealer travel coverage of up to 200 miles under warranty, according to Kohler.
Where Generac has the edge
- Dealer and parts network. Generac is the most widely installed brand, so in most areas you’ll find more authorized installers and parts on the shelf. After a hurricane, that can mean days less without a working generator.
- Range of sizes and options, from 10 to 26 kW air-cooled, with many transfer switch and load-management combinations.
- Familiarity. More technicians, including independent electricians, have worked on Generac units.
- Lower propane use at half load on the 26 kW (75 vs 85 cu ft/h), per the spec sheets.
What’s the same
Both use air-cooled V-twin engines, run on natural gas or propane, include an automatic transfer switch in common packages, exercise themselves weekly, offer app monitoring and carry a 5-year limited warranty as standard. Both need yearly maintenance.
How to decide
- Find the authorized dealers within 30 minutes of your home for each brand. If only one brand has a good local dealer, that settles it.
- If you’re on natural gas and your load is high, compare natural gas output, not headline kW.
- Get itemized quotes for both, with the same transfer switch amperage and the same scope of work.
- Read both warranty documents. Check labor, travel, registration requirements and hour limits.
Not sure what size you need? Start with the generator size calculator or our comparison of 14, 22 and 26 kW generators. For other brands, see Best Home Standby Generator Brands.
Fuel cost comparison over a 3-day outage
Using each manufacturer’s half-load figures and $15 per 1,000 cubic feet of natural gas:
| Generac 26 kW | Kohler 26RCAL | |
|---|---|---|
| Natural gas at ½ load | 188 cu ft/h | 180 cu ft/h |
| 72 hours of running | 13,536 cu ft | 12,960 cu ft |
| Approximate cost | About $203 | About $194 |
The difference is small; over a three-day outage, it’s roughly the price of a takeout dinner. Fuel use shouldn’t decide between these two units on its own.
Output on natural gas: the case where it does matter
Suppose your installer’s load calculation comes out at 23.5 kW peak on natural gas. Generac’s 26 kW is rated at 22.5 kW on natural gas, so it would need load management or a soft starter to cover that home. Kohler’s 26RCAL is rated at 24 kW, so it covers the load with a little margin. For homes that land in this narrow band, the natural gas rating is the most important number in the whole comparison. For most homes well below 22 kW, both units are more than enough.
On propane, the numbers flip
On natural gas Kohler is slightly more frugal, but on propane the spec sheets point the other way: 75 cubic feet of vapor per hour at half load for the Generac against 85 for the Kohler. Converted at roughly 36 cubic feet of vapor per gallon, and priced at $2.67 per gallon (the U.S. residential average we use across this site), that works out as follows:
| Generac 26 kW | Kohler 26RCAL | |
|---|---|---|
| Propane at ½ load | About 2.1 gal/h | About 2.4 gal/h |
| 72 hours of running | About 150 gallons | About 170 gallons |
| Approximate cost | About $400 | About $455 |
| Runtime on a 250-gallon tank (about 200 usable gallons) | About 4 days | About 3.5 days |
| Runtime on a 500-gallon tank (about 400 usable gallons) | About 8 days | About 7 days |
Tanks are normally filled to about 80% of capacity, which is why a 500-gallon tank holds about 400 usable gallons. These figures assume a steady half load around the clock; a house that runs its air conditioning hard will burn more, and one with modest loads at night will burn less. The practical takeaway is that on propane, the half-day difference in runtime matters more than the $55, because it decides how long you can wait for a delivery after a storm. If you’ll run either unit on propane, ask the installer to size the tank for the outage length you want to cover. Our propane use guide shows how.
Which one fits your home?
| Your situation | Leans toward | Why |
|---|---|---|
| Natural gas, peak load between about 22.5 and 24 kW | Kohler | Higher rated output on natural gas |
| Propane, long outages expected | Generac | Lower propane use at half load, longer tank runtime |
| Coastal home in a high-wind area | Kohler, if a good dealer is nearby | Published 181 mph enclosure wind rating |
| Rural area, few dealers of either brand | Whichever brand has the closest authorized service | Repair time after storms matters more than specs |
| Load well below 22 kW | Either; consider a smaller unit | A 26 kW unit may be more generator than you need |
The last row is worth taking seriously. Many homes that request quotes for 26 kW end up well covered by a smaller unit once a proper load calculation is done, especially with a soft starter on the air conditioner. A smaller unit costs less to buy and burns less fuel during a long outage.
Questions to ask each dealer
- How many units of this brand have you installed in the last year, and how many do you service?
- What transfer switch and load management options come in the package?
- What does the warranty cover for labor and travel, and for how long?
- Do you stock common parts, or are they shipped in after a storm?
- Is there a maintenance plan, and do plan customers get priority after storms?
Frequently asked questions
Is Kohler the same company as Rehlko?
Kohler’s home generators are now sold under the Rehlko company name, which is why Kohler home energy products appear on Rehlko websites. The products are still marketed with the Kohler name.
Which is quieter?
On paper they’re almost identical: 67 dB(A) in normal operation for both, and 56–57 dB(A) in exercise mode. Placement will make a bigger difference than the brand. See How Loud Is a Home Generator?
Which holds up better in hurricanes?
Kohler publishes a higher wind rating for its enclosure (up to 181 mph). In practice, correct installation, anchoring and placement matter as much as the rating. Ask your installer how the unit will be secured.
Bottom line
Generac’s and Kohler’s 26 kW units are closely matched on noise, warranty and features. Kohler has the edge on natural gas output and enclosure wind rating; Generac has the edge on propane consumption and, in most areas, on dealer and parts availability. Unless your load falls in the narrow band where the natural gas rating decides it, choose the brand whose local dealer you trust most, and compare itemized quotes with the same scope of work.