Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Coros - PACE 3 | Garmin - Fenix 8 Solar (47mm) |
|---|---|---|
| GPS mode | 38 h | 104 h |
| Smartwatch mode | 17 days | 28 days |
| Solar charging | false | true |
| ECG | false | true |
Between the PACE 3 and Fenix 8 Solar (47mm), the PACE 3 comes out ahead in several specs, while the Fenix 8 Solar (47mm) wins on gps mode / smartwatch mode. Overall, the PACE 3 scores 71.4 and the Fenix 8 Solar (47mm) scores 73.5 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (71.4 vs 73.5). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
The PACE 3 does not pull ahead on any single popular-comparison spec — its strengths sit in the spec-table groups rather than the headline advantages.
Pick the Fenix 8 Solar (47mm) if you care most about gps mode / smartwatch mode. Its strongest claims are gps mode, smartwatch mode, solar charging, among others. The single most decisive one: GPS mode — 173.68% more. 104 h vs 38 h.
Both ship with comparable multi-band gps, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Coros - PACE 3 or Garmin - Fenix 8 Solar (47mm)?
Garmin - Fenix 8 Solar (47mm) leads the current Mars Score by 2.1 points.The more useful decision is the trade-off behind that result: compare smartwatch mode, gps mode against the way you will actually use the product.
Choose Coros - PACE 3 if…
Coros - PACE 3 does not lead a decisive measured field here, so choose it for price, ecosystem, design, or availability when those matter more to you.
Choose Garmin - Fenix 8 Solar (47mm) if…
Garmin - Fenix 8 Solar (47mm) has the measurable edge on battery gps hours, battery smartwatch days, has solar.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Coros - PACE 3 wins
- No decisive advantages.
Why Garmin - Fenix 8 Solar (47mm) wins
- ▲GPS mode — 173.68% more. 104 h vs 38 h.
- ▲Smartwatch mode — 64.71% more. 28 days vs 17 days.
- ▲Has Solar charging.
- ▲Has ECG.
Spec comparison
GPS & Sensors
| Spec | Coros - PACE 3 | Garmin - Fenix 8 Solar (47mm) |
|---|---|---|
| Multi-band GPS | true | true |
| Barometric altimeter | true | true |
| Heart rate | true | true |
| ECG | false | truelead |
| Pulse Ox | true | true |
Battery
| Spec | Coros - PACE 3 | Garmin - Fenix 8 Solar (47mm) |
|---|---|---|
| Smartwatch mode | 17 days | 28 dayslead |
| GPS mode | 38 h | 104 hlead |
| Solar charging | false | truelead |
Design
| Spec | Coros - PACE 3 | Garmin - Fenix 8 Solar (47mm) |
|---|---|---|
| Case size | 42 mm | 47 mmlead |
| Weight | 39 glead | 82 g |
| Water resistanceⓘ | 5 ATM | 10 ATMlead |