Amazfit T-Rex Ultra 2 vs Garmin Enduro 3: AMOLED or 90-Day?

The Amazfit T-Rex Ultra 2 and Garmin Enduro 3 are both 51mm rugged adventure watches with multi-band GPS and 10 ATM water resistance, but they aim at very different buyers. One leans into AMOLED flash and aggressive pricing; the other leans into solar-assisted endurance and Garmin’s training depth. Below is the honest breakdown.

Key Differences

• Price gap: Amazfit launches at $549.99, Garmin at $899.99 — a $350 difference.
• Display tech: T-Rex Ultra 2 uses a 1.5-inch AMOLED at 480 x 480; Enduro 3 uses a 1.4-inch MIP at 280 x 280.
• Battery life: Enduro 3 triples the smartwatch endurance (90 days vs 30 days) and offers more than 6x the multi-band GPS time (13.3 days vs 2.1 days).
• Weight: Garmin is dramatically lighter at 63g vs Amazfit’s 89.2g, despite identical case sizes.
• Audio: Amazfit includes a mic and speaker for Bluetooth calls; Garmin omits both.
• Storage: Amazfit doubles it at 64GB vs 32GB on the Garmin.
• Ecosystem: Garmin Connect’s training, recovery, and coaching tools are still the gold standard for endurance athletes.

Deep Dive Comparison

Design & Comfort

Both watches share a 51mm case and a fiber-reinforced polymer body with a titanium bezel, but the experience on-wrist is night and day. The Enduro 3 weighs 63 grams — feather-light for a 51mm watch — thanks to Garmin’s nylon UltraFit strap and lean construction. The T-Rex Ultra 2 is heavier at 89.2 grams, with a chunkier, more tactical look that pairs Grade 5 titanium with a polymer base. If you sleep with your watch or run ultras, that 26-gram difference is real and you will feel it by hour 12.

Battery Life

This is where the Enduro 3 is in a different league. Garmin claims 90 days in smartwatch mode and 13.3 days of multi-band GPS tracking. The T-Rex Ultra 2 gets 30 days smartwatch and just 2.1 days of multi-band GPS. For day-to-day wear the Amazfit is still excellent, but if you are running a 100-miler or doing a multi-day FKT attempt without recharging, only the Enduro 3 finishes the job.

Health & Fitness Features

Both watches run multi-band GNSS, which is the spec that actually matters under tree cover and in canyons. The Enduro 3 uses Garmin’s Elevate Gen 5 heart-rate sensor with SpO2, plus a full sensor stack including barometer, altimeter, compass, gyroscope, accelerometer, and thermometer. The T-Rex Ultra 2 runs Amazfit’s BioTracker 6.0 PPG sensor with barometer, ambient light, and temperature. The bigger gap is the software: Garmin’s training load, recovery, race predictor, and adaptive coaching are years ahead of Zepp’s equivalents. If you want a watch that tells you what to do tomorrow, that’s Garmin.

Smart Features

The T-Rex Ultra 2 actually wins this round. It packs Bluetooth 5.2, Wi-Fi, NFC payments, a microphone, and a speaker — so you can take calls from the wrist and use Zepp’s offline voice assistant. The Enduro 3 has Garmin Pay over NFC and Wi-Fi, but no mic and no speaker, which means no on-watch calls. Storage also favors Amazfit at 64GB vs 32GB, useful if you load offline music or maps.

Price & Value

At $549.99, the T-Rex Ultra 2 is one of the best-priced rugged AMOLED multi-band GPS watches on the market. The Enduro 3 launches at $899.99 — a $350 premium that buys you triple the battery life, a lighter case, and Garmin’s training platform. Neither is overpriced for what it does, but the value calculation depends entirely on whether you actually need 13 days of GPS tracking.

Technical Specs

Spec	Amazfit T-Rex Ultra 2	Garmin Enduro 3
Launch Price	$549.99	$899.99
Case Size	51mm	51mm
Weight	89.2g	63g
Display	1.5-inch AMOLED, 480 x 480	1.4-inch MIP, 280 x 280
Water Rating	10 ATM	10 ATM
Battery (Smartwatch)	30 days	90 days
Battery (Multi-band GPS)	2.1 days (50 hours)	13.3 days (320 hours)
GPS	Multi-band	Multi-band
Sensors	BioTracker 6.0 PPG, accelerometer, gyroscope, barometer, ambient light, temperature	Elevate Gen 5 HR, SpO2, altimeter, barometer, compass, gyroscope, accelerometer, thermometer
NFC Payments	Yes	Yes
Mic & Speaker	Yes	No
Storage	64GB	32GB

The Verdict

The Garmin Enduro 3 wins for serious endurance athletes, full stop. If you run ultras, do multi-day adventures, or care about training metrics that actually move your performance forward, the 90-day battery, 13.3-day multi-band GPS, 63-gram weight, and Garmin Connect ecosystem are worth the $350 premium. Buy the Enduro 3 if your watch needs to outlast a 100-mile race or a week-long thru-hike on a single charge.

The Amazfit T-Rex Ultra 2 wins on screen, value, and smart features. Buy the T-Rex Ultra 2 if you want a vibrant AMOLED, on-wrist Bluetooth calls, NFC payments, and rugged styling for $549 — and you don’t need more than 50 hours of continuous multi-band GPS. For weekend hikers, gym lifters, and anyone whose longest day out is under 24 hours, it’s the smarter buy.

Frequently Asked Questions

Which watch has better battery life for ultra-marathons?

The Garmin Enduro 3, by a wide margin. It delivers 13.3 days of multi-band GPS tracking versus 2.1 days on the T-Rex Ultra 2 — meaning even a 100-mile race won’t put a dent in it. The Amazfit’s 50 hours is plenty for a single hard day, but it cannot finish a multi-day event without a recharge.

Is the AMOLED screen on the Amazfit worth giving up battery life?

Only if you wear the watch in casual settings often. The T-Rex Ultra 2’s 1.5-inch 480 x 480 AMOLED is sharper and more vivid than the Enduro 3’s 1.4-inch 280 x 280 MIP panel. But MIP excels in direct sunlight and sips power, which is why Garmin’s battery numbers are so much higher.

Why is the Garmin Enduro 3 $350 more expensive?

You’re paying for triple the battery life, a 26-gram lighter case, and Garmin’s training ecosystem, which still leads the industry for runners and triathletes. The Enduro 3 also adds SpO2 hardware and a full altimeter/compass/thermometer stack. If those things don’t matter to you, the T-Rex Ultra 2 delivers similar core hardware for $549.99.

Can I take phone calls from either watch?

Only the Amazfit T-Rex Ultra 2. It includes a microphone and speaker plus Bluetooth 5.2, so you can answer calls and use voice assistants from the wrist. The Garmin Enduro 3 has neither a mic nor a speaker — it can show notifications and reply with canned messages on Android, but it cannot place or take calls.

Which watch works better with iPhone versus Android?

Both pair fine with iPhone and Android, but Android users get more out of either. On Android, the T-Rex Ultra 2 supports text replies and the Enduro 3 supports canned message replies. iPhone users get notifications and core syncing on both, but Apple’s restrictions mean reply features are limited regardless of which watch you pick.