300 GTX
Twin outboards. 600 HP. A different power entirely.
The Granfort 300 GTX is powered by two Mercruiser Fourstroke V-8 4.5L 300HP outboard engines — 600 HP total. This is a fundamentally different boat from the 300 GTS, which uses a single inboard engine. The twin outboard configuration gives the GTX immediate, responsive power delivery, effortless joystick docking capability, and the confidence of redundant propulsion on the water.
At 9.10m LOA on a 2.80m beam, the 300 GTX produces a GPS-confirmed 49.9 mph top speed with 2 persons and — remarkably — 49.7 mph with 11 persons aboard. The hull barely notices the load. This is the factory test data: real numbers, named source, GPS-confirmed.
Starting at $234,700 with twin 200HP, or $265,500 fully configured with twin 300HP — the 300 GTX is the entry point to the Granfort twin outboard experience.
Interactive cockpit. Open bow. Gourmet stern.
The 300 GTX was designed for buyers who want the full social boat experience — a cockpit bar with cooler, fridge and sink, a lowered open bow with ample handrails, and a stern gourmet area complete with grill, table, sink and cup holders.
Real consumption numbers. Factory test. Named source.
All data from Fibrafort's published performance test FK 300 GT #007, conducted on Rio Itajaí-açu, Itajaí/SC, Brazil. Fuel consumption via engine instruments. Autonomy at 100% tank (520L). Combined consumption shown for both engines. 2-person test unless noted.
| RPM | Speed (knots) | Speed (mph) | Combined (L/h) | Combined (GPH) | Miles / Litre | Autonomy (miles) | Best use |
|---|---|---|---|---|---|---|---|
| 3,000 | 11.9 | 13.7 | 50.9 L/h | 13.4 GPH | 0.27 | 139 mi | Economy harbour cruise |
| 3,500 | 24.0 | 27.6 | 63.1 L/h | 16.7 GPH | 0.44 | 228 mi ⭐ | Best range point |
| 4,000 | 28.5 | 32.8 | 77.1 L/h | 20.4 GPH | 0.42 | 221 mi | Performance cruise (planing) |
| 4,500 | 32.8 | 37.8 | 98.8 L/h | 26.1 GPH | 0.38 | 199 mi | Sport cruise |
| 6,000 | 43.3 | 49.9 | ~195 L/h | ~51.5 GPH | 0.22 | ~108 mi | Top speed run |
Source: Fibrafort Performance Test FK 300 GT #007 — 2× Mercruiser Fourstroke V-8 4.5L 300HP · P17/DIAM16 INERTIA propellers · 2 persons · 50% fuel · 100% water · Rio Itajaí-açu, Itajaí/SC. Speed by GPS. Autonomy based on 100% tank capacity (520L / 137 gal). GPH converted from L/h (÷ 3.785). Combined figures shown for both engines.
What the data tells you: The 300 GTX sweet spot is 3,500 RPM — 27.6 mph comfortably on plane at 16.7 GPH combined, giving 228 miles of range. Cruise at 4,000 RPM (32.8 mph, 20.4 GPH) and you still get 221 miles. Even at 4,500 RPM (37.8 mph) range stays above 199 miles. At full power you reach 49.9 mph burning approximately 51.5 GPH combined — reserve that for the runs that deserve it.
The 300 GTX — every angle.
Designed for the water. Built to last.
Every number. Named source.
All specifications from Fibrafort's published performance test FK 300 GT #007 and the Granfort 300 GTX product page.
Hull & Dimensions
Engine & Drivetrain
Capacity & Storage
Published Performance · 2 Persons
Twin outboard power. Sport cruiser mission.
Why buyers choose the twin outboard 300 GTX
600 HP · twin Mercruiser V8 4.5L outboards
Two 300HP outboard engines producing 600HP total. The twin configuration delivers redundant propulsion, full joystick docking capability on equipped models, and the kind of responsive power delivery that transforms a 30ft boat into a genuine performance cruiser. 49.9 mph GPS-confirmed on the factory test.
5.91 seconds to plane — barely notices its load
The hull transitions from rest to fully on plane in under 6 seconds. More impressively: with 11 persons aboard it still planes in 8.04 seconds and hits 49.7 mph top speed. The difference between 2 and 11 persons at top speed is just 0.2 mph — remarkable hull efficiency at all load levels.
Cockpit bar + stern gourmet area
The cockpit features a side chaise, removable centre table, and a bar equipped with cooler, fridge, and sink. The stern platform adds a full gourmet area with grill, table, sink, and cup holders. Speakers throughout. This is a boat designed around the full day-on-the-water social experience.
228 miles range at best cruise speed
At 3,500 RPM (27.6 mph cruise), the 300 GTX delivers 228 nautical miles of range on its 520L tank — burning 16.7 GPH combined across both engines. Range stays above 199 miles all the way to 4,500 RPM. The 520L tank gives genuine coastal cruising range, not just a day-trip boat.
Built by Fibrafort · 35+ years · 18,000+ boats
Fibrafort construction — South America's #1
The 300 GTX is built by Fibrafort — the largest boat manufacturer in South America by units produced. 35+ years of production. 18,000+ boats delivered to buyers in 44 countries. The quality discipline behind every 300 GTX hull is built on that scale and experience.
Porsche Consulting-advised production processes
Fibrafort engaged Porsche Consulting to engineer the operational system that builds every hull. Published results: material costs -10%, excess parts orders -90%, reject rate reduced from 28 to 19 items, overtime -48%. The build quality behind the 300 GTX is measurable and published.
ABYC + U.S. Coast Guard certified
Published ABYC and U.S. Coast Guard certification for the American market. For U.S. buyers this is the clearest available documentation for insurance underwriting, financing, and long-term resale confidence. The certifications are published in the Granfort brochure — not available on request.
10-year structural warranty · hull and deck
Hull AND deck covered structurally for 10 years from new purchase — published in the Granfort brochure. Broader scope than most competitors in this segment. Request the full warranty document from your dealer before purchase.
What you actually pay. Published openly.
The 300 GTX is available with engine options from twin 200HP to twin 300HP, with Essential and Comfort packages available to build the exact specification you want.
Engine upgrades available: +$9,000 for twin 250HP · +$19,000 for twin 300HP V8 · +$39,500 for twin Verado 300HP + joystick. Essential Package ($29,900) includes ABYC pack, upgraded SIMRAD, electric winch, flaps, EVA carpet, bimini top and more. Comfort Package ($39,416) adds inverter, microwave, A/C 12,000 BTU, and Fischer Panda 5KVA generator.
Not a startup. South America's largest.
Granfort is the U.S. market brand of Fibrafort — a manufacturer with more production history behind its name than most buyers expect to find at this price.
50 mph.
600 HP.
Twin outboards.
Nothing communicates the 300 GTX like sitting at the helm and pushing the throttles forward. Sea trials are available weekly in Florida — private, no commitment, confirmation within 2 hours.
- 49.9 mph top speed · factory test FK 300 GT #007 · GPS confirmed
- 5.91 seconds to plane · 2 persons · 8.04 seconds · 11 persons
- 228 nautical miles best range at 3,500 RPM cruise
- Twin Mercruiser Fourstroke V-8 4.5L 300HP · 600HP total
- 10-year structural warranty · hull + deck · from day one
- ABYC + USCG certified · starting at $234,700
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