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.
- Wright Autonomous ZK 61 61G8 — commercial: daily paid use and high acreage; 61-inch deck; gas powered
- Grasshopper SO37 — commercial: daily paid use and high acreage; 61-inch deck; gas powered
What’s different? The 5 differences that matter most, from the published figures.
- Autonomous ZK 61 61G8 uses a Briggs & Stratton engine; SO37 uses a Vanguard engine. The engine maker builds the engine; the mower maker chooses the model, rating and fit, so the badge alone does not settle output or longevity.
- Autonomous ZK 61 61G8 has a Hydro transmission; SO37 has a T6 Drive Transmission transmission. The transmission grade tracks duty rating and speed. Grade names are each maker's own and are not comparable across brands.
- Autonomous ZK 61 61G8 has a published top speed of 12.5 mph; SO37 has a published top speed of 10.5 mph, a 2 mph difference. Top speed is the maker's maximum in transport. Mowing speed is lower and depends on grass, terrain and the deck.
- Autonomous ZK 61 61G8 holds 15.5 gal (58.7 L) of fuel; SO37 holds 13.5 gal (51.1 L) of fuel, a 2 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.
- Autonomous ZK 61 61G8 has a 40 hp engine; SO37 has a 37 hp engine, a 3 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.
1 more difference, calculated figures and what isn’t comparable
Other verified differences
- Autonomous ZK 61 61G8 weighs 1,310 lbs (594.2 kg); SO37 weighs 1,250 lbs (567 kg), a 60 lbs difference.
Calculated by MowerFacts
- Autonomous ZK 61 61G8 works out to 6.2 acres/hour; SO37 works out to 5.2 acres/hour, a 1.0 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
- Blades: not published for SO37.
- Deck Material: not published for SO37.
- Deck Construction: not published for SO37.
- Start Type: not published for SO37.
- Cut height range: not published for SO37.
- Price: Autonomous ZK 61 61G8 is dealer quote only.
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 | Autonomous ZK 61 61G8 Wright · Commercial |
SO37 Grasshopper · Commercial |
|---|---|---|
| List price | dealer quote | $13,365 |
| Engine | ||
| Power Source | gas | gas |
| Engine Make | Briggs & Stratton | Vanguard |
| Displacement | 60.6 ci (993 cc) | 60.6 ci (993 cc) |
| Engine Power | 40 hp | 37 hp |
| Cylinders | — | 2 |
| Engine Model | 61G8 | — |
| Fuel Type | Gasoline | Gasoline |
| Start Type | Electric | — |
| Deck | ||
| Cutting Width | 61 in (1549 mm) | 61 in (1549 mm) |
| Blades | 3 | — |
| Deck Material | 7 Gauge | — |
| Deck Construction | Floating-Mulch | — |
| Deck Gauge | 7 | — |
| Min Cut Height | 1.5 in (38 mm) | — |
| Max Cut Height | 5.5 in (140 mm) | — |
| Drive | ||
| Transmission | Hydro | T6 Drive Transmission |
| Ground Speed | 12.5 mph | 10.5 mph |
| Reverse Speed | 7 mph | — |
| Dimensions | ||
| Weight | 1310 lbs (594.2 kg) | 1250 lbs (567 kg) |
| Fuel Capacity | 15.5 gal (58.7 L) | 13.5 gal (51.1 L) |
| Length | 70 in (1778 mm) | — |
Where these models differ, explained
Autonomous ZK 61 61G8: Specs verified against the retailer listing on Jun 6, 2026 — barryspowerequipment.com.
SO37: Specs verified against the retailer listing on Jun 6, 2026 — tommysmotorsportscrossville.com.
Independent reference database. Specs compiled from manufacturer sources and normalized for comparison; verify with the manufacturer or dealer before purchase.