inboard outboard vs outboard fuel economy

I thought it would be a good idea to ask some current 1160 owners about their experience in fuel consumptions so I asked the Seawind owners group and out of a small but reliable sample size it seemed like the Yamaha outboards were seeing 1.5-2gph at ~6.5-7 knots boat speed and the yanmars were. According to Seawind the yanmars use about 70% the amount of fuel than the outboard options. One of the biggest factors in choosing which engines to go with are fuel consumption and range. Diesel inboards are known for their torque and will have considerable more torque than either of the outboard options. The 25hp high thrust outboards have about 60% more thrust in forward than the 20hp Hondas and 70% more thrust in reverse due in part to the fact that the Yamahas divert it’s exhaust out the leg instead of behind the prop in reverse. Hp is Hp at a given RPM but the things that can really fluctuate between these engines is torque and consumption. These may be minor points in the grand scheme of these option decisions but none-the-less things to consider. Would we prefer to have the diesel tanks which are located in the bilge and have extra storage in the lockers in front of the mast or have the gasoline tanks there and more storage in the hull bilges. Lastly, the tankage location is a consideration. could be transferable between all three engines. Additionally, if we chose the outboard option we could also choose the same exact engine for our tender so that parts, spares, filters, etc. In the case of gas outboards we would potentially have the same fuel source as our tender so that our spare fuel canisters could be extra capacity for both our tender or our main engines. In favor of gasoline as a fuel source, some people like the idea of having fewer different KINDS of fuel aboard. Many people argue that having diesel fuel onboard is safer than combustable gasoline which maybe true in theory but between ABYC standards and the quality that all Seawinds are known to be built to, it is unlikely that we would have a problem with gasoline stored and safely vented. Besides the obvious fuel capacity difference there are some other things to think about in this category. The 3ym30 yanmars come standard with about 95 gallon total capacity with each tank being located in the bilge area roughly centered for and aft in each hull.

The gasoline tanks total about 71.3 gallons and are located in external lockers just forward of the mast as to be isolated and vented overboard below the bridge deck. The Hondas and Yamahas obviously run on gasoline whereas the yanmars are diesel. To replace an inboard/outboard motor would be much more costly.We won’t get into exact costs here because they tend to fluctuate from the engine manufacturers and distributors but what we can say is the upgrades to the 25hp high thrust Yamahas costs less than 1% of the base price of the boat and upgrades to the Yanmar 3YM30 inboard diesels costs 6%-7% the base price of the boat. A boat equipped with an outboard is easier to repower or trade up to more HP or newer technology.In other words, more people want four-stroke outboards.* Fiberglass outboard registrations have historically outpace I/Os.Outboard motors are much more accessible and require less maintenance, no winterizing, and easier to work with the outboard outside the boat.Outboards have a more shallow draft allowing you to fish and boat in skinnier water than you can with an I/O.Typical a four-stroke outboard is approximately 400 to 500 pounds lighter than its inboard/outboard counterpart. Outboards offer better power to weight ratio.Four-stroke outboards offer much better fuel economy, less GPH, more MPG than I/O motors.The Yamaha four strokes offer higher performance–quicker to plane, quicker 0 to 30 MPH, and faster top-end per HP.I/O engines are in the cockpit which takes up a lot of the boat that can be used for other features and comfort. Outboards provide more room in the boat because they are installed on the transom, outside the boat.Inboard/outboards are just “marinized” automobile engines stuck in a boat. Outboards are designed specifically for boating.So why should you choose an outboard over a inboard/outboard motor? Here are just a few advantages the outboard has over the stern drives: That’s why all of NauticStar’s Deck Boats are factory installed with high performance Yamaha outboard motors. Inboard/Outboard Stern Drive Posted on MaJby NAUTICSTAR BOATSįour-stroke outboard motors are becoming increasingly popular over inboard/outboard stern drive motors on pleasure and ski boats for a variety of reasons.

Inboard outboard vs outboard fuel economy