PowerSmart 21 in 170cc RWD DB8621S
The cheapest way into a rear wheel drive 3-in-1 gas mower, for sloped lawns on a tight budget. Expect less dealer support than a Toro.
Amazon $339.99$339.99
The PowerSmart 21 in 170cc RWD DB8621S is the better lawn mower overall, rated 3.8 to 3.4. The PowerSmart 21 in 170cc RWD DB8621S leads on cutting modes and power. The PowerSmart 21 in 170cc RWD DB8621S costs $40 less ($339.99 vs $379.99).
PowerSmart B8721S1 Self-Propelled
#14 in Self-propelledFull review
A low cost rear wheel drive mower with a name brand engine, for sloped lawns up to a third of an acre that you bag or mulch.
Amazon $389.99 PowerSmart $379.99$379.99
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the PowerSmart 21 in 170cc RWD DB8621S for cutting modes (3 ways to cut: bag, mulch, side discharge vs 2 ways to cut: bag, mulch) and power (170 cc engine vs 140 cc engine).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every self-propelled lawn mower; a clear win is highlighted. How we rank explains each one.
| Factor weight | PowerSmart 21 in 170cc RWD DB8621S | PowerSmart B8721S1 Self-Propelled |
|---|---|---|
| Overall rating | 3.8/5 | 3.4/5 |
| Value 30% | 100 $16.19 per inch of deck ($339.99, 21 in deck) | 99 $18.09 per inch of deck ($379.99, 21 in deck) |
| Deck 20% | 12 21 in deck | 12 21 in deck |
| Power 15% | 62 170 cc engine | 25 140 cc engine |
| Cutting modes 15% | 100 3 ways to cut: bag, mulch, side discharge | 50 2 ways to cut: bag, mulch |
| Warranty 20% | 50 warranty not published (neutral score used) | 50 warranty not published (neutral score used) |
Specifications
| PowerSmart 21 in 170cc RWD DB8621S | PowerSmart B8721S1 Self-Propelled | |
|---|---|---|
| Cutting | ||
| Deck width | 21 in | 21 in |
| Deck | Steel | Steel |
| Cutting height | 1.5 to 3.9 in, 6 positions | 1.5 to 3.9 in, 6 positions |
| Bag | Yes | Yes |
| Bag capacity | - | 1.7 bushels |
| Mulch | Yes | Yes |
| Side discharge | Yes | No |
| Power | ||
| Power | Gas | Gas |
| Engine or battery | 170 cc | 140 cc (Briggs & Stratton E550) |
| Electric start | No | No |
| Build | ||
| Drive | Rear-wheel drive | Rear-wheel drive |
| Folds upright | Yes | - |
| Weight | 59 lb | 70 lb |