JOHN DEERE644k

John Deere 644 Key Specs (General Reference) • Production Year: Ranges by variant; G/P/X-Tier ~2018–present; K-Series ~2014–2021 • Engine Manufacturer: John Deere, Model PowerTech™ 6068H (6.8L, 6-cylinder) • Emission Standard: US Tier 2/Stage II → Tier 4 Final/Stage V (varies by year/region) • Engine Net Power: 169–185 kW (227–248 HP) @ 1,800 RPM (ISO 9249) • Auxiliary Hydraulic Flow: 223–330 L/min (59–87 GPM) (closed-center, axial-piston) • Max Speed: 40 km/h (24.9 mph) (forward); ~25–26 km/h (reverse) • Operating Weight: 17.9–18.8 tons (17,934–18,892 kg) • Transport Dimensions (L×W×H): ~8.08–8.72 m × 2.77–3.04 m × 3.45–3.46 m • Gross Operating Weight: 17,934–18,892 kg (39,537–41,571 lb) • Counterweight: ~1,400–1,800 kg (varies by configuration) • Bucket Capacity: 3.1–3.6 m³ (4.0–4.75 cu yd) (heaped); 2.5–3.2 m³ (3.2–4.25 cu yd) (struck) Note: Values vary by model year, tier (G/P/X/K), and configuration. For exact specs, confirm with your John Deere dealer or the official spec sheet for your target variant.