Compare Mowers
List prices are the manufacturer’s published figures, re-checked daily; they exclude tax, freight and dealer setup.
A side-by-side reference of each model's stated specifications. MowerFacts doesn’t give opinions: where a published, spec-derived rule can separate machines we mark a Data Pick and show the rule; here, read the values and decide what fits your needs.
Best suited for
What each model is built for, from its duty class and key specs. This is a neutral reference — MowerFacts does not rank one model above another.
- Scag SWZ Hydro-Drive — commercial: daily paid use and high acreage; 36-inch deck; gas powered
- Scag SFC-21 — commercial: daily paid use and high acreage; 21-inch deck; gas powered
What’s different? The 5 differences that matter most, from the published figures.
- SWZ Hydro-Drive lists at $8,449 to $11,329; SFC-21 lists at $1,699 to $2,049, a $6,750 difference. List price is the maker's own figure before tax, freight and dealer setup. Dealers set the final price.
- SWZ Hydro-Drive has a 14 hp engine; SFC-21 has a 4 hp engine, a 10 hp difference. Published horsepower is the maker's rating at a stated engine speed. It is a different measure from displacement, and two engines of equal rating can pull differently.
- SWZ Hydro-Drive weighs 515 lbs (233.6 kg); SFC-21 weighs 136 lbs (61.7 kg), a 379 lbs difference. Operating weight bears on trailer payload, ramps and soft turf. On its own it says nothing about build quality. What SWZ Hydro-Drive's weight means for a trailer ›
- SWZ Hydro-Drive holds 5.5 gal (20.8 L) of fuel; SFC-21 holds 0.4 gal (1.4 L) of fuel, a 5.1 gal difference. Tank size bounds how long a machine runs between stops. Consumption varies with engine, load and speed, so hours per tank are not fixed.
- SWZ Hydro-Drive has a 36 in (914 mm) deck; SFC-21 has a 21 in (533 mm) deck, a 15 in difference. Deck width sets how much grass each pass covers. Mowing time also depends on ground speed, turns and obstacles, so a wider deck alone does not fix the job's length. Time both decks on your own lawn ›
3 more differences, calculated figures and what isn’t comparable
Other verified differences
- SWZ Hydro-Drive uses a Kawasaki® FS Series engine; SFC-21 uses a Honda engine.
- SWZ Hydro-Drive has a published top speed of 7.4 mph; SFC-21 has a published top speed of 4.2 mph, a 3.2 mph difference.
- SWZ Hydro-Drive cuts from 1.7 in (44 mm) to 4.5 in (114 mm); SFC-21 cuts from 1.5 in (38 mm) to 4.5 in (114 mm).
Calculated by MowerFacts
- SWZ Hydro-Drive works out to 2.2 acres/hour; SFC-21 works out to 0.7 acres/hour, a 1.4 acres/hour difference. Calculated by MowerFacts from deck width and the published top speed at 80% efficiency; it is not a manufacturer figure, and real mowing is slower.
Not comparable
- Displacement: not published for SWZ Hydro-Drive.
- Transmission: not published for SWZ Hydro-Drive.
- Drive System: not published for SFC-21.
Verified means each manufacturer publishes the figure. A bigger number is only a bigger number; nothing here says which machine is better. The full specification table is below.
Which is faster on your property? › Measure your lawn once and MowerFacts times all 2 against it.
| Spec | SWZ Hydro-Drive Scag · Push / Walk-Behind |
SFC-21 Scag · Push / Walk-Behind |
|---|---|---|
| List price | $8,449–$11,329 | $1,699–$2,049 |
| Engine | ||
| Power Source | gas | gas |
| Displacement | — | 9.9 ci (163 cc) |
| Engine Power | 14 hp | 4 hp |
| Cylinders | — | 1 |
| Engine Make | Kawasaki® FS Series | Honda |
| Deck | ||
| Cutting Width | 36 in (914 mm) | 21 in (533 mm) |
| Min Cut Height | 1.7 in (44 mm) | 1.5 in (38 mm) |
| Max Cut Height | 4.5 in (114 mm) | 4.5 in (114 mm) |
| Deck Construction | Dual-plate cutter deck constructed of 2 steel plates. Reinforcement plate at cutter deck spindles. | 14 gauge deck with 14-gauge replaceable guards for strength and longevity. Deep draw stamped. |
| Drive | ||
| Transmission | — | GT MG 512 transmission, 3-speed |
| Ground Speed | 7.4 mph | 4.2 mph |
| Drive Tire Size | 16″ x 6.5″-8″ | — |
| Reverse Speed | 3 mph | — |
| Drive System | Dual Pump and Motor | — |
| Dimensions | ||
| Weight | 515 lbs (233.6 kg) | 136 lbs (61.7 kg) |
| Fuel Capacity | 5.5 gal (20.8 L) | 0.4 gal (1.4 L) |
| Commercial / Pro | ||
| Seat Type | n/a | — |
Where these models differ, explained
SWZ Hydro-Drive: Specs verified against the manufacturer spec sheet on Jun 6, 2026 — scag.com.
SFC-21: Specs verified against the manufacturer spec sheet on Jun 6, 2026 — scag.com.
Independent reference database. Specs compiled from manufacturer sources and normalized for comparison; verify with the manufacturer or dealer before purchase.