Diesel outboards

That would be right, a single fuel simplifies logistics. "Collisions" making petrol dangerous, seriously dumb, considering that very few cars burst into flame in accidents.

 

What are the top 100 likely problems?

 

Ribeye leads UK boatbuilders in ordering new OXE300 for Superyacht tenders from Proteum - Proteum https://proteum.co.uk/newsevents/news/ribeye-leads-uk-boatbuilders-ordering-new-oxe300-superyacht-tenders-proteum/

 

Fire isn't a recognized issue with outboard motors, simple as that, if that is the selling point of diesel outboards, they won't sell.

 

I get your point on the fire and am not arguing it with you. I’m just curious what the 100 actual items are that you referred to. I presume it wouldn’t include any of the ABYC & USCG & EU/RCD fuel and electrical system code requirements for outboard motors.

 

I think the market is people that cant or wont have petrol and thats it.
That market although small its one that can pay.
Will it have EU and EPA compliance?

 

OXE outboards are being marketed in the US and plans have been announced to build the outboards in the US. https://www.tradeonlytoday.com/industry-news/oxe-diesel-outboards-to-be-built-in-u-s Therefore they must meet EPA regulations. OXE Diesel outboards are marketed to commercial users: OXE Diesel - Worlds leading outboard diesel engines https://www.oxe-diesel.com/
A photo on the website shows two OXE outboards on a USCG boat. I don't know if the USCG is a customer or if that was a test installation. OXE DEALER - DIESEL OUTBOARDS https://www.oxedealer.com/
The move to co-brand with BMW suggests OXE outboards will also be marketed to customers interested in "premium" products. https://images.saymedia-content.com/.image/cs_srgb/MTc0MTY4NjQyNzE0NDc4MDc2/oxemarine.pdf

Cox 300HP Diesel outboards are being marketed as more fuel efficient, higher torque and longer life: The CXO300 Diesel Outboard Engine - Cox Marine https://www.coxmarine.com/the-engine/
Production Cox Diesel outboards will soon arrive in the US: Cox production diesel outboards make their way to North America - Cox Marine https://www.coxmarine.com/first-300hp-diesel-outboards-roll-off-the-production-line-ready-for-delivery-2/

 

Cox indicated they have their EPA Tier 3 approval which they need to sell in the US. They will also be RCD/EU certified for Europe. From what I’ve read the pricing is about $56k plus controls, but someone told me the price would be going up before the end of 2020. There’s a lot of articles on this website for both products.
Cox - Diesel Outboard News https://dieseloutboardnews.com/manufacturer/cox/

I’ve yet to see OXE press release that they’ve received their EPA Tier 3 approval which they will no doubt release as soon as they receive it. I was quoted approximately $57k plus controls at the 2020 Miami show.
OXE Diesel - Diesel Outboard News https://dieseloutboardnews.com/manufacturer/oxe-diesel/

Neither of the products has been proven in the field with large scale usage so its hard to tell how they will perform and hold up. Cox released fuel numbers on an Intrepid boat last year that were not great but rumor is they made a change to the fuel system. The belt drive is the big difference for OXE and they’ve been more involved with the USCG testing as part of the program to fulfill a long standing desire for a Single Fuel policy. However, the military diesel is much different than either of these common rail motors require so not too sure how they meet that target.

 

You and I both know, the "100" was "poetic licence". However, we know diesel fuel has greater calorific value, by some margin, over petrol, so in theory there should be a significant fuel saving for the same output, it becomes a question of how many thousands of hours of running before the initial cost is defrayed, by the fuel savings, and whether the engine will last long enough, without major rebuild, or replacement, to start enjoying that advantage. I would also factor in the consideration of diesel fumes, which most people probably find more objectionable than unleaded gasoline. I suppose considerations of weight are also potentially important, and the smaller the boat, the more important that becomes.

 

In the Midwest USA diesel has been running close to $3\gal while regular gasoline has been around $2.20. With the much higher cost of diesel fuel, most perceptions of fuel cost savings disappear. Diesel engines with current emission controls use a similar amount of fuel unless heavily loaded when the differences are more marked. Towing a gooseneck one might get 10mpg or less on gas and 12mpg on diesel. Then the diesel Option when buying might add $10k to the price of a 3/4 ton truck.

So the concept that there is a savings to diesel power is not universal. When the diesel engine then proves to be unreliable, that really sours the deal...

 

Yes, a gap has opened in the price of the fuels, which does not go toward making diesel more attractive. There may be niche applications where diesel outboards are the preferred option, but they would be few. I think if there is a significant weight penalty, it becomes even less practicable. We have come a long way from what was the original concept of an outboard motor, which was of light weight, easily fitted power.

 

"Poetic License" gets old when someone is driving their opinion with it. I do agree that there are definitely a combination of different features/benefits, of which not all would appear to fit every single boaters usage patterns. When doing an estimation by comparing the 300 Hp diesel fuel curves from an inboard diesel against a 31’ Pursuit tested by BoatTest.com with Yamaha F300 it's 3,000 hrs to reach payback in the U.S. (using standard pump prices for fuel), but around 1,500 hours in Europe based on their fuel prices. This is looking at a duty cycle of running a range between 60% - 80% load, however if it was run more WOT the payback would be much quicker (the engine life would clearly be less in that case). I believe Europe also allows reclaiming the VAT on diesel for commercial users so it would likely be even fewer hours in that case. However, you can’t compare gas/diesel prices at the auto pumps in the mid-west and apply that across the board. Most marinas in the U.S. sell higher octane petrol on the water, and where its still available they sell non-ethanol as well. Therefore, when buying fuel on the water diesel is almost always considerably cheaper. Fuel Price Reports | Chesapeake & Delaware Bays https://www.waterwayguide.com/fuel-price-report

The diesel outboards being Tier 3 compliant are much better on emissions and the environment. Also, realize there are already ECA zones and IWP standards that went into effect last year, and preclude the use of a petrol outboard in these areas based on their current emissions output. The current petrol regulations of the newest 4 stroke engines are in line with the automotive emissions regulations of the 1980's. The major petrol outboard manufacturers have design protected for the addition of the catalyst. You'll see the catalyst become a requirement for the petrol products in the next 2-3 years. Looking at how it impacted the inboard industry, the retail cost to the consumer went up about 30%. Payback between petrol and diesel outboards will get much closer after this happens.

 

I watched an interesting story today which backed up what I have been saying about the long life of modern 4 stroke outboards. Pennicott eco tours In Tasmania run 60 yamaha 250 hp 4 strokes and 6 v8s. They change the motors at between 3500 and 5500 thousand hours. They have a waiting list of pro and private buyers waiting to buy the motors as they come off the boats and in 10 years of selling high hour yamaha not one has ever come back with problems. And some of those have added thousands more hours on top of what they had already done. So it makes a lot more sense to stick with petrol outboards that last for thousands of hours than a diesel that costs a fortune and has a short service life.

 

What sort of weight penalty is there with diesel outboards ? That would, or should, factor in to decisions. 4S petrol are heavy enough.

 

Personally I don't care much for the testing being done by various entities like USCG. A moderate amount of hours over a short period of time says little about how an engine performs in real life. Regular use/misuse over a long period of time, not necessarily many running hours, is worth more in my book.

For many (especially commercial operators), fuel consumption isn't the only factor when deciding what powertrain to use. Maintenance and noise etc can also be high on the list.