Granfort 300 GTS Boat: A Masterpiece of Design, Performance, and Luxury
300 GTS
A single inboard. A different character entirely.
The Granfort 300 GTS is powered by a single Mercruiser 6.2L V8 350HP DTS inboard engine — not outboards. This is a fundamentally different boat from the 300 GTX, which uses twin outboards. The inboard drivetrain gives the GTS a distinct feel: lower centre of gravity, cleaner hull lines below the waterline, and the deep, purposeful sound of a V8 at full throttle.
At 9.10m LOA on a 2.80m beam, the 300 GTS is built for buyers who want the engaged, connected feel of an inboard sport cruiser at 30 feet — with a cockpit designed for entertaining and a cabin below for weekend stays.
The performance data on this page comes directly from Fibrafort's published factory test (Test FK 300 GT #014) — conducted on Rio Itajaí-açu, Itajaí/SC, Brazil, with speed measured by GPS. Real numbers. Named source. No marketing estimates.
Social cockpit. Weekend cabin. V8 inboard soul.
The 300 GTS is designed for buyers who want a sport cruiser that is genuinely alive at the helm — not just a platform for passengers. The cockpit is social. The cabin is comfortable. And the Mercruiser V8 reminds you why inboards exist.
Real consumption numbers. Factory test. Named source.
All data below is from Fibrafort's published performance test FK 300 GT #014, conducted on Rio Itajaí-açu, Itajaí/SC, Brazil. Fuel consumption measured via engine instruments. Autonomy calculated at 100% tank capacity (380 litres). 6-person test shown.
| RPM | Speed (knots) | Speed (mph) | Consumption (L/h) | Consumption (GPH) | Miles per Litre | Autonomy (miles) | Best use |
|---|---|---|---|---|---|---|---|
| 3,000 | 8.6 | 10.0 | 36.7 L/h | 9.7 GPH | 0.27 | 103 mi | Fuel economy cruise |
| 3,500 | 10.1 | 11.7 | 49.6 L/h | 13.1 GPH | 0.23 | 158 mi | ⭐ Best range point |
| 4,000 | 13.3 | 15.3 | 67.2 L/h | 17.7 GPH | 0.23 | 145 mi | Performance cruise |
| 4,500 | 26.5 | 30.6 | 73.3 L/h | 19.4 GPH | 0.42 | 126 mi | Sport cruise (planing) |
| 5,000 | 31.0 | 35.7 | 93.8 L/h | 24.8 GPH | 0.38 | 127 mi | Fast cruise |
| 5,300 | 33.0 | 38.0 | 114.6 L/h | 30.3 GPH | 0.33 | 126 mi | Top speed run |
Source: Fibrafort Performance Test FK 300 GT #014 — Mercruiser 6.2L 350HP DTS · P19 propeller · 6 persons · 50% fuel · 100% water · Rio Itajaí-açu, Itajaí/SC, Brazil. Speed by GPS. Autonomy based on 100% tank (380L). GPH converted from L/h (÷ 3.785).
What the data tells you: The most efficient cruising point is 3,500 RPM — 11.7 mph at 13.1 GPH giving 158 miles of range. The "sweet spot" for range on the 300 GTS is a comfortable harbour-to-harbour cruise speed. When you want performance, 4,500 RPM puts you planing at 30.6 mph on 19.4 GPH. Top speed of 38 mph at 5,300 RPM consumes 30.3 GPH — reserve that for the runs that deserve it.
The 300 GTS on the water.
Granfort 300 GTS — in motion
Single Mercruiser V8 · 38 mph · Inboard sport cruiser
Every number. Named source.
All specifications from Fibrafort's published performance test FK 300 GT #014 and the Granfort 300 GTS product brochure.
Hull & Dimensions
Engine & Drivetrain
Capacity & Storage
Published Performance · 6 Persons
Inboard character. Sport cruiser mission.
Why buyers choose the inboard 300 GTS
Mercruiser 6.2L V8 DTS — single inboard
350 HP of V8 inboard torque. Digital Throttle and Shift for precise, effortless control at all speeds. The DTS system eliminates cable stretch and mechanical play — helm response is instant and consistent from idle to wide open throttle.
Clean hull below the waterline
The inboard drivetrain means no outboard brackets, no transom weight concentration, and no propeller exposure when swimming. The hull runs clean from stem to stern — better hydrodynamics, lower drag, and a swim area clear of machinery.
V8 acoustic signature
The Mercruiser V8 delivers a sound profile that twin outboard configurations cannot replicate. At idle it is a low, settled burble. At full throttle it is purposeful and direct. For buyers who care about how the boat feels to drive — the inboard experience is distinct.
15.91 seconds to plane — 6 persons
Factory-tested with six people aboard at 50% fuel and full water. Minimum planing speed: 27.0 mph. At 4,500 RPM the hull is planing comfortably at 30.6 mph on 19.4 GPH. Performance you can use every weekend, not just on an empty test lake.
Built by Fibrafort · 35+ years · 18,000+ boats
Fibrafort construction — South America's #1
The 300 GTS 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 the 300 GTS is built on that scale.
Porsche Consulting-advised production processes
Fibrafort engaged Porsche Consulting not to style the boat, but to engineer the operational system that builds it. Published results: material costs -10%, excess parts orders -90%, reject rate reduced from 28 to 19 items, overtime -48%.
ABYC + U.S. Coast Guard certified
The Granfort range carries published ABYC and U.S. Coast Guard certification. For American buyers this is the clearest available documentation for insurance underwriting, financing, and long-term resale confidence.
10-year structural warranty · hull and deck
Published in the Granfort brochure. Hull AND deck covered structurally for 10 years from new purchase. Request the full warranty document from your dealer before purchase — specific, written, and verifiable from day one.
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.
One run on
the water and
it's obvious.
The single Mercruiser V8 inboard experience is not something a spec sheet fully communicates. Sea trials are available weekly in Florida — private, no commitment, confirmation within 2 hours.
- 38 mph top speed · factory test FK 300 GT #014 · GPS confirmed
- Single Mercruiser 6.2L V8 350HP DTS · inboard drivetrain
- Best range: 158 nautical miles at 3,500 RPM cruise (13.1 GPH)
- 10-year structural warranty · hull + deck · from day one
- ABYC + U.S. Coast Guard certified · published in brochure
- Built by Fibrafort · 35+ years · 18,000+ boats · 44 countries
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