Generac GP6500 COsense vs Westinghouse WGen5300s
The Generac GP6500 COsense is the more powerful unit: 6,500 running watts against 5,300 — about 18% more capacity for the Generac GP6500 COsense. The Generac GP6500 COsense runs longer at half load — 11.5 hours on its 7.9-gallon tank vs 11 hours.
| Generac GP6500 COsense | Westinghouse WGen5300s | |
|---|---|---|
| Type | portable | portable |
| Fuel | gasoline | gasoline |
| Running watts (gas / LP for standby) | 6500 W | 5300 W |
| Starting watts (gas) | 8125 W | 6600 W |
| Noise level | — | 68 dBA |
| Runtime at 50% load (gas) | 11.5 h | 11 h |
| Runtime at 25% load (gas) | — | 14.5 h |
| Fuel tank | 7.9 gal | 4.7 gal |
| Output voltage | 120/240V | — |
| Transfer-switch-ready outlet | 30 A | 30 A |
| Start type | recoil | electric |
| CO safety shutoff | Yes | — |
| Engine displacement | 389 cc | 274 cc |
| Weight | 172 lb | 131.4 lb |
Frequently asked questions
Which is more powerful, the Generac GP6500 COsense or the Westinghouse WGen5300s?
The Generac GP6500 COsense, at 6,500 running watts on its best fuel versus 5,300 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 Generac GP6500 COsense or the Westinghouse WGen5300s?
Estimated fuel for 24 hours at about 50% load: $53 on gasoline for the Generac GP6500 COsense vs $33 on gasoline for the Westinghouse WGen5300s, 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.