Diesel Outboards: Ready for Prime Time?

It might seem surprising how little headway diesel outboards have made in the marine marketplace, especially considering the enhanced reliability, torque, and efficiency diesels provide. Weight and size have always been their main barriers, but in today’s world of 1,000-pound outboards that tower over the transom it would no longer seem to be quite the same issue it once was. But, are diesel outboards ready for prime time in the first place?

In the past few years we’ve seen a couple of new players enter this segment. Oxe Marine, a Swedish company which has been working to expand its presence in the US market for several years, currently offers models in 150, 175, 200, and 300 horsepower, plus has a 450 hp diesel-electric hybrid concept motor. The 300 tips the scales at 870 pounds, which is around 300 pounds more than a Yamaha F300. Cox Marine Diesel has just two models, but they’re big ones at 300 and 350 hp (which both weigh in at about 800 pounds).

There’s no question that these engines offer spectacular economy, in some cases getting 80-plus percent more range out of the same amount of fuel. Weight is obviously still an issue, though less so than one might have guessed. They also have an absurd amount of torque as compared to gas, and while we don’t have the years on ownership required to truly rate them for reliability, as a rule diesel always wins out over gas. But – there’s always a but – when running these motors the most jarring difference we’ve experienced is a longing for the whisper-quiet idling of a modern four-stroke gasoline outboard. Diesels are noisier and cause more vibrations, and this is true in outboards as well as in automobiles. Then, there’s cost to consider. These engines post sticker prices around double that for a gasoline outboard.

So, back to the original question: are they ready for prime time? Well, yes they are. However, for the average recreational boater their downsides are still likely to outweigh their advantages. Naturally there will be some circumstances where these motors will be the top pick, like for fleets commercial vessels, or for use as tenders with montherships full of diesel fuel. But for the average angler, the question really isn’t if they’re ready. It’s if they’re the top choice for your needs.