AMERISUN 21-Inch 3IN1 Push Gas Lawn Mower with vs RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah
Updated July 2026 — AMERISUN 21-Inch 3IN1 Push Gas Lawn Mower with wins on weight and cutting width, RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah wins on battery.
The AMERISUN mower offers more versatility and power, while the RB mower is lightweight and budget-friendly.
Why AMERISUN 21-Inch 3IN1 Push Gas Lawn Mower with is better
Power
144cc engine vs 40V battery
Versatility
3-in-1 mowing options vs limited cutting heights
Cutting Width
21-inch deck vs 9-inch deck
Why RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah is better
Weight
68 lbs vs 11.5 lbs
Price
$238.49 vs $169.99
Storage
Compact design vs larger footprint
Overall score
Specifications
| Spec | AMERISUN 21-Inch 3IN1 Push Gas Lawn Mower with | RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah |
|---|---|---|
| Engine Type | Gas | Battery |
| Cutting Heights | 6 | 3 |
| Maintenance | Regular | Low |
| Start Type | Recoil | Electric |
| Safety Features | Basic | Advanced |
Dimension comparison
Price Comparison
The AMERISUN 21-Inch 3IN1 Push Gas Lawn Mower is priced at $238.49, while the RB 9" Small Lawn Mower for Small Spaces costs $169.99. This makes the RB mower about 29% cheaper than the AMERISUN model. The significant price difference may appeal to budget-conscious consumers, especially those who have smaller yards and may not need the additional features of a gas mower. While the AMERISUN mower offers a broader range of functionality suited for larger areas, the RB mower’s lower cost makes it a practical option for those with limited outdoor space.
Performance and Power
When it comes to performance, the AMERISUN lawn mower features a powerful 144cc 4-stroke OHV engine that is designed for strong cutting power and smooth operation. In contrast, the RB mower is powered by a 40V 2Ah battery and features a brushless motor that operates at a high speed of 6000 RPM. While the AMERISUN mower is designed for small to medium yards, the RB mower is optimized for smaller lawns, making it effective for areas up to 540 square feet. The choice between gas and battery power could influence potential buyers depending on their specific yard size and mowing requirements.
Cutting Versatility
The AMERISUN mower offers a 3-in-1 mowing capability, including mulching, bagging, and side discharge options. This versatility allows homeowners to choose how they want to manage clippings, making it suitable for various lawn care needs. The RB mower, while more limited with only three cutting height adjustments ranging from 1.2" to 2", still provides adequate customization for small yards. The ability to mulch and bag in the AMERISUN mower provides a significant advantage for those looking to maintain a healthy lawn, whereas the RB mower's simplicity could be sufficient for basic lawn care.
Size and Weight
The AMERISUN mower weighs 68 lbs, making it relatively lightweight for a gas mower. This weight allows for easier maneuverability compared to many traditional gas mowers. On the other hand, the RB mower is exceptionally lightweight, weighing only 11.5 lbs without the battery. Its ultra-light and compact design makes it highly maneuverable, particularly in tight corners and small areas. For users who prioritize ease of handling and storage, the RB mower's lightweight nature and space-saving design may be more appealing.
Ease of Use
In terms of ease of use, the AMERISUN mower features an easy-start recoil system for hassle-free starting and a foldable handle for convenient storage. It is designed for those who may be accustomed to traditional gas mowers. Conversely, the RB mower boasts one-hand steering and pivoting front wheels, making it very user-friendly, especially for beginners. Additionally, the advanced safety design of the RB mower ensures it automatically stops if tilted beyond a certain angle, adding an extra layer of safety for users. This ease of use could be a deciding factor for those new to lawn care.
Maintenance Requirements
The AMERISUN mower, being a gas model, requires regular maintenance typical of gas engines, such as oil changes and fuel management. This can involve more effort compared to electric models. The RB mower, however, is maintenance-free due to its brushless motor, which does not require oil changes or fuel management, making it a low-maintenance option for casual users. For individuals looking for a mower that demands minimal upkeep, the RB mower is more appealing in this regard.
Storage and Portability
The AMERISUN mower's foldable handle allows for easier storage, but its overall size and weight mean it may take up more space in a garage or shed. In contrast, the RB mower features a detachable aluminum handle and an upright storage design, allowing it to save up to 70% of space. This makes it ideal for those with limited storage options. If portability and compact storage are significant factors for potential buyers, the RB mower stands out as the more practical choice.
Which should you buy?
Choosing between the AMERISUN 21-Inch 3IN1 Push Gas Lawn Mower and the RB 9" Small Lawn Mower ultimately depends on your specific needs and yard conditions. If you have a small to medium yard and value versatility in cutting options, the AMERISUN mower may be the better fit despite its higher price. However, if you're looking for a lightweight, compact, and budget-friendly option for a small lawn, the RB mower presents a compelling choice with its ease of use and minimal maintenance requirements.

