Greenworks 40V 21" Brushless Cordless (S vs SENIX 22 Inch 3-in-1 Gas Lawn Mower, 201

Greenworks 40V 21" Brushless Cordless (Self-Propelled) Lawn Mower (75+ Compatible Tools), 5.0Ah Battery and Charger Included
Greenworks 40V 21" Brushless Cordless (Self-Propelled)...
$399.99
★ 4.1/5 · 1527 reviews
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SENIX 22 Inch 3-in-1 Gas Lawn Mower, 201cc Rear Wheel Single Speed Self-Propelled Mower, 4-Cycle Engine, Steel Deck, Mulching, Bagging, Discharging, 6-Position Cutting Height Adjustable, for Yard
SENIX 22 Inch 3-in-1 Gas Lawn Mower, 201cc Rear Wheel...
$431.99
★ 4.4/5 · 386 reviews
Read full review →
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Quick Verdict

The Greenworks 40V 21" cordless electric mower is the better choice for most homeowners who value quiet operation, low maintenance, and convenience on smaller, flat lawns. The SENIX 22-inch gas mower wins for those with larger yards, thicker grass, or uneven terrain where raw power and longer run time without battery swaps matter more. Neither is a universal winner—your choice depends on yard size, terrain, and willingness to manage fuel or batteries.

Side-by-Side

Feature Greenworks 40V 21" Brushless Cordless SENIX 22 Inch 3-in-1 Gas, 201cc
Price $399.99 $431.99
Power Source 40V battery (brushless motor) 201cc gas engine
Cutting Width 21 inches 22 inches
Best Yard Size Up to 1/3 acre (single charge) 1/4 to 1/2 acre (continuous fuel)
Self-Propelled Yes (variable speed) Yes (single speed rear-wheel)
Mulch/Bag/Side Discharge Yes (3-in-1) Yes (3-in-1)
Weight (approx.) ~65 lbs (with battery) ~85 lbs (with oil/gas)
Noise Level Quiet (under 80 dB) Loud (90+ dB)
Maintenance None (no oil, gas, spark plugs) Oil changes, fuel stabilizer, air filter

Where Greenworks Wins

  • Zero maintenance: No gas, oil, spark plugs, or carburetor cleaning. Just charge and mow.
  • Quiet operation: Mow early or late without disturbing neighbors. No earplugs required.
  • Instant start: Push a button and go. No pull cord, choke, or priming.
  • Lighter weight: Easier to maneuver and push, especially on slopes or tight spots.
  • Variable-speed self-propulsion: Adjust ground speed to your walking pace, unlike the SENIX’s single-speed drive.
  • Lower long-term cost: No fuel or oil purchases. Battery and charger included at $400.

Where SENIX Wins

  • More cutting power: The 201cc engine handles thick, damp, or overgrown grass that can bog down a 40V electric.
  • Continuous run time: No battery swaps for large lawns. Refuel in seconds, not recharge hours.
  • Wider cut: 22 inches vs. 21 inches means slightly fewer passes on a large lawn.
  • Proven reliability for heavy use: Gas engines tolerate frequent use on tough terrain without battery degradation over years.
  • No charging wait: Use immediately if gas is in the tank. No planning around battery charge cycles.
  • Better for rough ground: Heavier build and gas torque handle uneven, bumpy yards more consistently.

Which Should You Buy

Buy the Greenworks 40V if: Your yard is under 1/3 acre, mostly flat, and you want the simplest, cleanest mowing experience. It’s ideal for anyone tired of gas engine maintenance, noise, or smell. The self-propulsion is smoother, and the $32 price difference is negligible given the long-term savings on fuel and oil.

Buy the SENIX gas mower if: Your lawn is over 1/3 acre, has thick or tall grass, or includes slopes where battery power might fade. The single-speed drive is less refined, but the 201cc engine won’t quit mid-yard. It’s also better if you don’t want to manage battery charging or replacement costs after a few seasons.

Bottom line: For convenience and low upkeep, choose the Greenworks. For raw power and endurance