Greenworks 40V 21" Brushless Cordless (S vs SENIX 22" Self-Propelled Gas Lawn Mower
Quick Verdict
The Greenworks 40V 21" cordless mower wins for homeowners with small to medium lawns who want quiet, low-maintenance operation and reliable self-propelled assistance. The SENIX 22" gas mower is the better choice for those with larger, more demanding yards who need raw power, longer run time, and the included trimmer for complete lawn care.
Side-by-Side
| Feature | Greenworks 40V 21" Brushless Cordless | SENIX 22" Self-Propelled Gas + 17" Trimmer |
|---|---|---|
| Price | $399.99 | $579.00 |
| Power Source | 40V battery (brushless motor) | 170cc gas engine + 26.5cc gas trimmer |
| Cutting Width | 21 inches | 22 inches |
| Self-Propelled | Yes | Yes |
| Best Yard Size | Up to 1/3 acre | 1/3 to 1/2 acre |
| Rating | 4.1/5 (1,527 reviews) | 4.0/5 (463 reviews) |
| Included Extras | Battery and charger | 17-inch gas trimmer |
Where Greenworks Wins
Lower upfront cost. At $399.99, the Greenworks is $179 less than the SENIX, making it a better value for budget-conscious buyers.
Quieter, cleaner operation. No gas, no fumes, no pull-start hassle. The brushless motor runs quietly and starts instantly with a button press.
Lighter weight and easier handling. Without a gas engine, the Greenworks is noticeably lighter, reducing fatigue during use. The 21-inch deck is also slightly narrower, making it more maneuverable in tight spaces.
Lower maintenance. No oil changes, spark plug replacements, or fuel stabilizer needed. Store it for winter without any prep work.
Stronger user satisfaction. With a 4.1/5 rating from over 1,500 reviews, the Greenworks has a larger sample size and higher average score, indicating consistent reliability.
Better for small lawns. The 40V battery provides enough power for most lawns under 1/3 acre on a single charge, and the brushless motor maximizes efficiency.
Where SENIX Wins
More raw power. The 170cc gas engine delivers higher torque and sustained power, easily handling thick, wet grass and uneven terrain without bogging down.
No battery range anxiety. Gas mowers run as long as you have fuel, making the SENIX ideal for larger yards or properties with multiple grass areas. No need to wait for a battery to recharge.
Wider cutting deck. The 22-inch deck cuts a 1-inch wider path than the Greenworks, reducing mowing time on larger lawns.
Includes a gas trimmer. The $579 price includes a 17-inch 26.5cc gas trimmer, adding significant value for those who also need edging and trimming equipment. This combo saves you from buying a separate trimmer.
Better for tough conditions. The gas engine handles hills, thick grass, and overgrown areas more effectively than most cordless models.
No battery degradation. Gas mowers don’t lose capacity over time. A well-maintained SENIX will perform the same years later, while batteries eventually need replacement.
Which Should You Buy
Choose the Greenworks 40V 21" if: You have a lawn up to 1/3 acre, prefer quiet operation, don’t want to deal with gas and oil, and want to save nearly $180. It’s also the better choice if you value lighter weight and easier storage. The 1,500+ reviews and 4.1 rating suggest it’s a proven, reliable performer for typical suburban yards.
**Choose the SENIX