Gardena
Comparison · 2 robots
Gardena Sileno Minimo · Greenworks Optimow 15
All robot lawn mowers. Every measure below is plotted against the full class, so a difference can be read against how much the class itself varies.
- Gardena Sileno Minimo
- Greenworks Optimow 15
01 Classification
What each one does on its own.
The Autonomy Ladder is the same five rungs for every robot on the site. A rung describes the conditions a robot handles without you, not how good it is.
V
Generalized
Any task, any setting
IV
Environmental
Handles new obstacles without help
III
Conditional
Finishes familiar jobs on its own
II
Assisted
Runs preset routines, needs rescue
Gardena Sileno MinimoGreenworks Optimow 15
I
Manual
One action, on command
02 Assessment
Where they actually differ.
The Robovations Score is nine inputs across three pillars, each weighted as shown and each scored so that more is better. A robot can lead on one and trail on another, which is the point of showing them apart. Cost of ownership and data handling are reported on each robot's own page and are never averaged into the score.
Capability
Task completion16% of score
Does it finish the job it is sold to do, unattended
7575
- Gardena Sileno Minimo75
- Greenworks Optimow 1575
18median 72 across 433 scored robots100
Coverage and navigation10% of score
Does it work the whole area, and hold that between runs
5555
- Gardena Sileno Minimo55
- Greenworks Optimow 1555
0median 70 across 421 scored robots100
Edge-case recovery10% of score
Does it recover from the failures its category presents
5065
- Gardena Sileno Minimo50
- Greenworks Optimow 1565
18median 52 across 320 scored robots100
Operating envelope4% of score
How far conditions can vary before performance drops
6476
- Gardena Sileno Minimo64
- Greenworks Optimow 1576
28median 68 across 397 scored robots100
Dependability
Field failure rate16% of score
Documented hardware failures per owner-year
10064
- Gardena Sileno Minimo100
- Greenworks Optimow 1564
6median 70 across 359 scored robots100
Software stability14% of score
Whether updates fix more than they break
6582
- Gardena Sileno Minimo65
- Greenworks Optimow 1582
15median 65 across 342 scored robots100
Support longevity10% of score
Committed parts, service and updates, with dates
9758
- Gardena Sileno Minimo97
- Greenworks Optimow 1558
0median 62 across 429 scored robots100
Ownership burden
Routine maintenance12% of score
Hands-on time it asks for in normal operation
5143
- Gardena Sileno Minimo51
- Greenworks Optimow 1543
22median 67 across 434 scored robots100
Consumables8% of score
Parts that must be bought to keep it working
10076
- Gardena Sileno Minimo100
- Greenworks Optimow 1576
8median 69 across 434 scored robots100
03 Measured against the class
How far apart is a long way?
A number only means something next to the spread it sits in. Each track below is the real range across every classified robot in the class, with the median marked.
Runtime107 with a published figure
65 min70 min
- Gardena Sileno Minimo65 min
- Greenworks Optimow 1570 min
30 minmedian 100 min240 min
Charge time108 with a published figure
60 min70 min
- Gardena Sileno Minimo60 min
- Greenworks Optimow 1570 min
30 minmedian 90 min300 min
Noise105 with a published figure
57 dB50 dB
- Gardena Sileno Minimo57 dB
- Greenworks Optimow 1550 dB
50 dBmedian 60 dB82 dB
Weight120 with a published figure
15.4 lbs24.3 lbs
- Gardena Sileno Minimo15.4 lbs
- Greenworks Optimow 1524.3 lbs
13 lbsmedian 30.4 lbs134 lbs
Height121 with a published figure
9.5 in10.2 in
- Gardena Sileno Minimo9.5 in
- Greenworks Optimow 1510.2 in
7.5 inmedian 11 in16.5 in
Not compared, because fewer than two of these robots carry a published figure: Price, Suction.
04 Ownership
What the numbers leave out.
The trade-off
What each design gives up to be good at what it is good at.
Gardena Sileno Minimo
Wire guidance trades upfront infrastructure burden for stability. Installation takes 2-4 hours; the system then runs reliably for years with minimal edge-case surprises, but annual wire maintenance never goes away.
Greenworks Optimow 15
Wire installation is the price of entry: the Optimow 15 delivers genuine unsupervised mowing, but only after the owner commits several hours to perimeter-wire layout and staking.
Randomized cutting works, but systematic GPS-based mowing completes large areas faster and with more predictable pass distribution; the Optimow 15 trades path efficiency for a lower price tier.
Who each one is wrong for
Stated by the record itself. A robot being wrong for a household is a fact about fit, not a fault.
Gardena Sileno Minimo
- Yards over half acre or complex boundaries
- Spec limit is 500 sqm. Wire-guided systems struggle with narrow passages, multiple disconnected zones, or organic irregular boundaries. Larger properties exceed design scope.
- Steep slopes exceeding 15% gradient
- Gardena sets two slope limits, not one: 25 percent inside the work area, with anything steeper isolated by the boundary wire, and 10 percent at the boundary itself. Where the lawn edge is steeper than 10 percent, the wire has to be laid 20 cm (8 in.) in from the edge.
- Owners wanting zero perimeter maintenance
- Boundary wire requires annual inspection, repair of breaks, and seasonal reconnection. RTK-based mowers eliminate this; wire-guided alternatives cannot.
Greenworks Optimow 15
- Yards exceeding 1,500 m² (0.37 acres)
- The 1,500 m² coverage ceiling is a documented hard limit. Larger properties require a higher-capacity model; exceeding the rated area results in incomplete coverage cycles.
- Owners who cannot or will not install perimeter wire
- The Optimow 15 requires perimeter wire for all boundary definition. No GPS or camera-based wire-free operation is supported. Wire installation is mandatory, not optional.
- Properties with dense obstacles or numerous internal garden beds
- Randomized-pattern mowers lack systematic zone mapping. Dense obstacle fields or numerous internal garden beds require extensive guide-wire loops, adding installation complexity and wire-break risk.
- Slopes exceeding 35% or areas with loose surface conditions
- The 35% gradient rating is the published hard limit. Steeper sections or slopes with wet clay at the boundary are outside the documented operating envelope.
- Households requiring Wi-Fi or local-network integration
- Connectivity runs over GSM (cellular module), not home Wi-Fi. Smart-home integrations dependent on local Wi-Fi are not supported on this model.
What stays your job
The upkeep ownership hands back to you, whatever the autonomy level says.
Gardena Sileno Minimo
- Seasonally: Deploy mower, verify boundary wire integrity (visual inspection), test dock connection (5-10 minutes).
- Weekly (during season): Inspect the blades for wear or damage, as Gardena recommends.
- Every 4-7 weeks (during season): Replace all three blades and their screws together (about $5 per change; the kit holds nine blades and nine screws, three changes).
- After every 5-10 uses: Clear deck and blade area of grass clippings and debris.
- Monthly (during season): Check dock contacts for corrosion; clean if needed. Inspect visible boundary wire for breaks.
- Annually: Full boundary wire inspection and repair of any breaks or corrosion damage. Dock connector replacement if corroded.
Greenworks Optimow 15
- After every use: Visually inspect blade disc for damage or grass clogging.
- Weekly: Clear accumulated clippings from the chassis underside and blade housing.
- Monthly: Inspect boundary wire and pegs along the full perimeter; re-stake any lifted sections.
- Every 3-6 months: Replace blade disc or individual blades; standard Greenworks Optimow replacement parts.
- Seasonally: Clean charging contacts on dock and mower body; verify boundary wire continuity before mowing season.
- Annually: Full perimeter wire inspection; replace degraded sections; charge battery to storage level before winter.
05 Evidence
How much each of these is standing on.
Classifications rest on different depths of evidence. A pre-release assessment and a verified one are not the same kind of claim.
| Robot | Evidence status | Sources reviewed | Last assessed |
|---|---|---|---|
| Gardena Sileno Minimo | Provisional | 4 | Aug 2026 |
| Greenworks Optimow 15 | Pending | — | Aug 2026 |
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