MerCruiser's Horizon inboards are classic performers, with proven technology that's virtually maintenance-free

  • Near-universal dealer and technician training on Horizon inboard models
  • Electronic multiport fuel injection affords instant startup, effortless cruising and quintessential MerCruiser reliability
  • Closed-cooling technology dramatically reduces potential for corrosion, extending the life of your engine and your boating season
  • Stainless steel exhaust, durable designs and simple maintenance all contribute to remarkably easy ownership
Exceptional Selection

MerCruiser is the only company that offers both sterndrive and inboard gasoline engines. We know that one size doesn't fit all, which is why we give you the choice of the best marinized versions of each technology. MerCruiser has the broadest horsepower range (135 to 430 hp) in these categories, as well, and no one else offers a comparable lineup of catalyzed sterndrive and inboard engines.

Innovation is Standard

State-of-the-art technology is the norm at MerCruiser. For you, that means cutting-edge features come standard on every Horizon inboard, including Mercury's SmartCraft Digital Throttle & Shift. Boaters rave about the precise throttle response and effortless steering delivered by the DTS system. MerCruiser Horizon inboards also boast standard MerCruiser Emissions Control Technology (ECT), which allows you to cruise cleanly without any loss of power, performance or fuel efficiency.

Got Your Back

All MerCruiser Horizon inboards come with a standard four-year limited corrosion warranty as well as a standard three-year limited factory-backed warranty - which includes a fourth year if your boat builder has participated in the MerCruiser Installation Quality certification program. Need more assurance? Nobody has more factory-trained service dealers than MerCruiser, so if you ever have an issue or need to talk to an expert, there's bound to be one close by.

HP/kW 320 / 239
Full throttle RPM 4600-5000
Cylinder Configuration V-8
Displacement (L) 6.2
Alternator Amp 65 amp / 917 watt
Cooling Systems Brass sea water pump
Closed cooling
Long life 5-year antifreeze
Water Drain Systems Single point air actuated
Recommended Oil Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMA FC-W rated
Recommended Fuel 87% octane / up to 10% ethanol
Engine Guardian System SmartCraft Engine Guardian
Emissions Control Technology Yes*
Boat Types Tow Sports/Ski Boat

Inboards Resources

Buy the Books

You can order all available Mercury literature online or through any authorized Mercury dealer. Please have your outboard or sterndrive serial number before placing the order.

  • Operation, Maintenance and Warranty Manuals
  • Parts Manual
  • Service Manual
Purchase a Manual
Request a Brochure

Request printed brochures by mail or download as an electronic PDF.

Request a Brochure
Installation Drawings

Installation drawings are technical documents, detailing the dimensions of the engines to facilitate installation in new or repowered boats.

Installation Drawings

Related Documents

Sustainability Report Fuel Care