Diesel Outboards? Why Not?

Just because half the lakes in the country are covered with ice doesn't mean we can't think about the upcoming boating season. Eric Haun, editor of Marine News, wrote an interesting article last summer in Marine Link titled "Making the Case for Diesel Outboards." In it he shares insights about transitions taking place in the marine arena.

Haun begins by pointing out how more and more professionals are switching away from inboard motors to outboards on small military craft, workboats, patrol boats another others kinds of vessels that were historically inboard engine powered. This gives the boats several advantages including easier access to maintenance, quicker replacement and the extra space available inside the boat.

At this point the discussion turns to diesel outboards, which have advantages of their own, one of the foremost being fuel safety. The author writes, Compared to gasoline, diesel is a less flammable fuel and therefore much safer to work with in all working environments. In addition, with diesel engines the combustion of fuel takes place due to the heat generated by the compression of fuel and air inside the cylinder. Compression ignition is safer than petroleum being ignited by a spark plug, or any other spark.

One of Haun's sources was OXE Marine, a Sweden-based diesel outboard manufacturer. According to Myron Mahendra, CEO of OXE Marine, “Many vessels are hindered by regulations to carry petrol onboard if fire safe containment is not provided. The use of petrol is, therefore, a challenge for any vessel with tenders.”

He also spoke with U.K.-based Cox Powertrain, which makes diesel outboards as well. Cox noted that NATO has been pushing a single fuel idea, with the aim of maximizing equipment interoperability by using a single fuel option. This is one of the drivers behind the CXO300 diesel outboard Cox Powertrain has developed.

The end result here is that rescue vessels, naval and military vessels can refuel at the mother ship without being burdened with the hazard of highly volatile gasoline.

"Another benefit associated with diesel is efficiency," writes Haun. "Both Cox and OXE point to significant fuel savings compared to gas. Cox claims its 300-horsepower CXO300 offers roughly 30% fuel savings compared to its gasoline equivalent, while Mahendra says the 300-horsepower OXE 300, due to enter production shortly, uses up to 42% less fuel than a comparable gasoline outboard."

This fuel efficiency results in greater operational range so boats can stay out on the water longer.

Diesel outboards also have the usual advantages of diesel engines, including endurance, torque and flexibility. Though the price advantage goes to gas-powered outboards, one can make up the difference by comparing the life cycle costs of each and in most applications this would be fairly even.

The full article can be found here, with more photos as well.
https://www.marinelink.com/news/making-case-diesel-outboards-479456