Head-to-Head Comparison

Updated September 5, 2026

Citizen Tsuyosa Automatic (Green Dial) vs Seiko 5 Sports GMT SSK001

Citizen's timepiece meets Seiko's GMT watch

Quick Verdict

The Citizen Tsuyosa Automatic (Green Dial) ($250–$500) and Seiko 5 Sports GMT SSK001 ($250–$500) are closely matched timepieces at similar price points. The Tsuyosa Automatic (Green Dial) emphasizes Citizen/Miyota In-House Automatic engineering while the 5 Sports GMT SSK001 focuses on Made in Japan craftsmanship.

CitizenTsuyosa Automatic (Green Dial)$250–$500 Check price Seiko5 Sports GMT SSK001$250–$500 Check price

Transparency — We earn a small commission on purchases made through our Amazon links. This doesn't affect our editorial independence.

Citizen

Tsuyosa Automatic (Green Dial)

$250–$500

Check Price Full Review

Seiko

5 Sports GMT SSK001

$250–$500

Check Price Full Review

Specifications Compared

Feature	Citizen Tsuyosa Automatic (Green Dial)	Seiko 5 Sports GMT SSK001
Price	$250–$500	$250–$500
Case Size	40mm	42.5mm
Movement	Automatic Caliber 8210	Automatic Caliber 4R34 (True GMT)
Caliber Type	Citizen/Miyota In-House Automatic	Seiko In-House Automatic GMT
Power Reserve	40 Hours	41 Hours
Water Resistance	50m (5 ATM)	100m (10 ATM)
Crystal	Sapphire Crystal with Cyclops	Hardlex Crystal
Case Material	Stainless Steel	Stainless Steel
Origin	Made in Japan	Made in Japan

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Citizen's design language vs Seiko's approach

The Citizen Tsuyosa Automatic (Green Dial) features a Stainless Steel case at 40mm with Sapphire Crystal with Cyclops protection. The Seiko 5 Sports GMT SSK001 offers Stainless Steel construction at 42.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Seiko

Automatic Caliber 8210 vs Automatic Caliber 4R34 (True GMT)

The Tsuyosa Automatic (Green Dial) runs the Automatic Caliber 8210 (Citizen/Miyota In-House Automatic, 40 Hours power reserve) at 21,600 vph (3 Hz) frequency. The 5 Sports GMT SSK001 uses the Automatic Caliber 4R34 (True GMT) (Seiko In-House Automatic GMT, 41 Hours reserve) at 21,600 vph (3 Hz). The 5 Sports GMT SSK001 offers a longer power reserve.

📏

Wearability & Fit

Edge: Citizen

40mm vs 42.5mm — different wrist presence

At 40mm, the Tsuyosa Automatic (Green Dial) wears more compactly on smaller wrists compared to the 5 Sports GMT SSK001 at 42.5mm. Water resistance differs: 50m (5 ATM) vs 100m (10 ATM).

💰

Value & Cost of Ownership

Edge: Draw

Same tier — different value propositions

The Citizen Tsuyosa Automatic (Green Dial) sits at $250–$500 and the Seiko 5 Sports GMT SSK001 at $250–$500. On the specs that outlast any price: the Tsuyosa Automatic (Green Dial) uses Sapphire Crystal with Cyclops with 40 Hours, against Hardlex Crystal and 41 Hours on the 5 Sports GMT SSK001. Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Seiko

50m (5 ATM) vs 100m (10 ATM)

The Tsuyosa Automatic (Green Dial) is rated to 50m (5 ATM) while the 5 Sports GMT SSK001 handles 100m (10 ATM). The 5 Sports GMT SSK001 offers superior water resistance.

Our Verdict

Citizen

Tsuyosa Automatic (Green Dial)

Choose the Citizen Tsuyosa Automatic (Green Dial) if you prioritize Citizen/Miyota In-House Automatic engineering, Made in Japan craftsmanship, and 50m (5 ATM) water resistance. At $250–$500, it delivers Automatic Caliber 8210 with 40 Hours power reserve.

Check Price on Amazon

Seiko

5 Sports GMT SSK001

Choose the Seiko 5 Sports GMT SSK001 if you value Seiko In-House Automatic GMT technology, Made in Japan heritage, and 42.5mm proportions. At $250–$500, the Automatic Caliber 4R34 (True GMT) with 41 Hours power reserve makes it a compelling choice.

Check Price on Amazon

Try Prime Free — Free Shipping on Both Watches Students & 18–24: start Prime for Young Adults free

The Bottom Line

The Citizen Tsuyosa Automatic (Green Dial) and Seiko 5 Sports GMT SSK001 represent two distinct approaches to fine watchmaking — the Citizen bringing Made in Japan tradition while Seiko delivers Made in Japan engineering.

Frequently Asked Questions

For water, the Seiko 5 Sports GMT SSK001 is rated 100 m against 50 m, which is the difference between swimming and diving on one side and splashes on the other. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.

Both are priced similarly, making this a question of preference rather than value. The Tsuyosa Automatic (Green Dial) emphasizes Citizen/Miyota In-House Automatic technology while the 5 Sports GMT SSK001 prioritizes Seiko In-House Automatic GMT precision.

Both are suitable for daily wear. The Tsuyosa Automatic (Green Dial) at 40mm with 50m (5 ATM) water resistance handles everyday situations. The 5 Sports GMT SSK001 at 42.5mm with 100m (10 ATM) is similarly capable. The Tsuyosa Automatic (Green Dial) uses Sapphire Crystal with Cyclops while the 5 Sports GMT SSK001 uses Hardlex Crystal.

More Comparisons

Citizen Tsuyosa Green vs Seiko 5 Sports

Sapphire and 50m against Hardlex and 100m

Tag Heuer Carrera Chronograph vs Citizen Tsuyosa Automatic (Green Dial)

Tag Heuer's chronograph meets Citizen's timepiece

Tag Heuer Carrera Chronograph vs Seiko 5 Sports GMT SSK001

Tag Heuer's chronograph meets Seiko's GMT watch

Explore These Watches

Citizen Tsuyosa Automatic (Green Dial) — Full Review Seiko 5 Sports GMT SSK001 — Full Review Browse All Guides

How This Page Was Made

Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.