Kohler 12RESV 12kW vs Kohler 14RCAL 14kW with ATS
The Kohler 14RCAL 14kW with ATS is the more powerful unit: 14,000 running watts against 12,000 — about 14% more capacity for the Kohler 14RCAL 14kW with ATS. The Kohler 14RCAL 14kW with ATS is the quieter of the two (67 dBA vs 69 dBA — though manufacturers measure noise at different loads and distances).
| Kohler 12RESV 12kW | Kohler 14RCAL 14kW with ATS | |
|---|---|---|
| Price (MSRP) | $4,283 | — |
| Type | home-standby | home-standby |
| Fuel | natural-gas, propane | natural-gas, propane |
| Running watts (gas / LP for standby) | 12000 W | 14000 W |
| Running watts (propane) | 12000 W | 14000 W |
| Running watts (natural gas) | 11000 W | 12000 W |
| Noise level | 69 dBA | 67 dBA |
| Output voltage | 120/240V | 120/240V |
| Automatic transfer switch included | No | Yes |
| Main-line circuit breaker | 60 A | — |
| Start type | automatic | automatic |
| Engine | Kohler KT725 | Kohler CH740 |
| Engine displacement | 725 cc | 725 cc |
| NG use at half load | 128 ft³/h | 124 ft³/h |
| Propane use at half load | — | 1.65 gal/h |
| Weight | 433 lb | 440 lb |
| Warranty | 5 yr | 5 yr |
Frequently asked questions
Which is more powerful, the Kohler 12RESV 12kW or the Kohler 14RCAL 14kW with ATS?
The Kohler 14RCAL 14kW with ATS, at 14,000 running watts on its best fuel versus 12,000 W. Remember that dual-fuel and natural-gas ratings are lower than gasoline ratings — the comparison table shows the published per-fuel figures.
Which costs less to run, the Kohler 12RESV 12kW or the Kohler 14RCAL 14kW with ATS?
Estimated fuel for 24 hours at about 50% load: $46 on natural gas for the Kohler 12RESV 12kW vs $44 on natural gas for the Kohler 14RCAL 14kW with ATS, at national average prices. These are spec-sheet-derived estimates — the assumptions are on the methodology page, and different fuels make this a cost comparison, not an efficiency ranking.
Where do these specifications come from?
Every record on BackupAtlas is hand-curated from manufacturer documentation and spec sheets, and each generator page links to its source document.