Greenworks 40V 21" Brushless Cordless (S vs BILT HARD 21" Self Propelled Gas Lawn Mo
Quick Verdict
The Greenworks 40V 21" Brushless Cordless (Self-Propelled) and the BILT HARD 21" Self Propelled Gas Lawn Mower (201cc 4-Cycle) are both strong contenders in the sub-$400 self-propelled mower market, each earning a 4.1/5 rating. The Greenworks wins for homeowners with small to medium yards (under 1/3 acre) who prioritize quiet operation, zero emissions, and low maintenance. The BILT HARD wins for those with larger or thicker lawns (up to 1/2 acre or more) who need the sustained power and runtime that only gas can provide, especially on hills or wet grass.
Side-by-Side
| Feature | Greenworks 40V 21" Brushless Cordless | BILT HARD 21" Self Propelled Gas (201cc) |
|---|---|---|
| Price | $399.99 | $389.99 |
| Power Source | 40V lithium-ion battery (2 included) | 201cc 4-cycle gas engine |
| Cut Width | 21 inches | 21 inches |
| Best Yard Size | Up to 1/3 acre | Up to 1/2+ acre |
| Self-Propelled | Yes (variable speed) | Yes (single speed) |
| Weight | ~55 lbs (with battery) | ~65 lbs |
| Noise Level | Quiet (low 70s dB) | Loud (mid 90s dB) |
| Maintenance | Minimal (blade sharpening, battery care) | Oil changes, spark plugs, air filters, fuel |
Where Greenworks Wins
Low maintenance and instant start. The Greenworks requires no gas, oil changes, spark plugs, or carburetor cleaning. You press a button and mow. This saves time and money over the life of the mower.
Quieter operation. At roughly 20 dB lower than gas mowers, the Greenworks lets you mow early or late without disturbing neighbors. It’s also easier on your hearing.
Lighter and more maneuverable. At about 10 pounds lighter than the BILT HARD, the Greenworks is easier to push, turn, and lift for storage. The variable-speed self-propelled drive lets you match your walking pace.
Better for the environment. Zero emissions and no fuel spills. The 40V battery system also works with other Greenworks tools (trimmers, blowers).
Foldable handle and upright storage. The Greenworks handle folds for compact storage without requiring you to drain fuel or worry about leaks.
Where BILT Wins
Unlimited runtime. With a full tank of gas, you can mow for 45–60 minutes continuously. No waiting for batteries to recharge (Greenworks: ~30–60 min runtime per charge, 60+ min recharge time). For yards over 1/3 acre, the BILT HARD finishes in one go.
More raw power for tough conditions. The 201cc engine easily handles tall, wet, or thick grass that can stall a cordless mower. It also powers through hills and uneven terrain without bogging down.
Lower upfront cost. At $389.99, the BILT HARD is $10 cheaper than the Greenworks. Over time, gas costs add up, but the initial purchase is slightly less.
Proven gas reliability. A 4-cycle engine is simple to maintain if you’re comfortable with basic small engine care. Parts and service are widely available.
Single-speed self-propel is simple. No electronics to fail; just engage and go. The drive system is mechanical and robust.
Which Should You Buy
Buy the Greenworks 40V 21" Brushless Cordless if: