Our verdict
Pick the M57 if you want a snap-action Mighty-Mate with stainless hardware at a lower price. Pick the M63 for more rated flow (up to 4,320 GPH), an LED plug and a five-year limited warranty.
The central trade-off
Flow. Up to 2,580 GPH for the M57 and up to 4,320 GPH for the M63, per Zoeller.
Warranty. The M63's five-year limited warranty is its strongest point.
Shared design. Both are oil-filled cast iron with solid floats and vortex impellers.
Side by side
| Specification | Zoeller M57 Mighty-Mate Sump Pump | Zoeller M63 Sump Pump |
|---|---|---|
| Horsepower | Not stated by the maker | 3/10 HP |
| Max flow (maker) | 43 GPM | 43 GPM |
| Max head (maker) | 19.25 ft | Not stated by the maker |
| Switch | Not stated by the maker | Not stated by the maker |
| Housing | cast iron | Cast Iron |
| Discharge | Not stated by the maker | Not stated by the maker |
| Power cord | Not stated by the maker | 9 foot cord |
| Weight | 27.1 lb | Not stated by the maker |
| Warranty | Not stated by the maker | Not stated by the maker |
Values are the makers' published specifications. "Not stated" means the maker doesn't publish it.