Amazfit T-Rex 3 vs Garmin Forerunner 165
Amazfit T-Rex 3 (42 h GPS, 68 g) vs Garmin Forerunner 165 (19 h GPS, 39 g). Side-by-side spec comparison: battery, weight, maps, multi-band GPS and price. Which GPS watch should you buy?
AmazfitAmazfit T-Rex 3Ultra-rugged outdoor watch with dual-band GPS, offline maps and a 2,000-nit AMOLED display, at a mid-range price. 42 h in maximum-accuracy mode and up to 27 days in daily use. Military standard, 100 m water resistance and onboard music. Garmin Instinct-style toughness for far less.
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GarminGarmin Forerunner 165Entry-level running watch with a 1.2" AMOLED display, 19 h GPS battery and just 39 g. Training metrics, adaptive plans and accurate multi-GNSS GPS for training and racing marathons. Garmin's gateway watch for runners who don't need maps or multi-band.
View on AmazonSpec-by-spec comparison
| Spec | Amazfit T-Rex 3 | Garmin Forerunner 165 |
|---|---|---|
| GPS battery | 42 h | 19 h |
| Multi-band battery | Yes | – |
| Smartwatch | 27 days | 11 days |
| Weight | 68 g | 39 g |
| Maps | ✓ | – |
| Multi-band | ✓ | – |
| Music | ✓ | – |
| Display | AMOLED | AMOLED |
| Price | Entry | Entry |
GPS battery = each manufacturer's standard GPS mode; multi-band = dual-frequency (maximum accuracy). On Suunto, Polar Grit and Amazfit T-Rex the GPS figure already corresponds to dual-band mode. Figures verified against the manufacturer.
Verdict
For maximum autonomy on long ultras, Amazfit T-Rex 3 lasts longer in GPS mode. If you want the lightest watch on your wrist, go for Garmin Forerunner 165. Only Amazfit T-Rex 3 brings onboard topo maps for navigation. Both sit in the same price segment, so let battery, weight and the feature you value most decide.