Hourly Cost to Run a Diesel Engine?

[Chipg]

Hi everyone,

I'm trying to estimate the hourly cost to run a common diesel in the75hp range, not including fuel, just maintenance, oil, oil filters, air filters, belts, hoses, water pumps etc.

In aviation we have a pretty good idea of what it cost to run an airplane and prorate hourly expeses.

I'm not loking for a short term example but someting over 2,000 hours of experience.

Would you guys say (excluding fuel) it cost about $1 an hour? $2 an hour? $3 an hour to maintain / operate it?

Thanks!

[Chief Engineer]

2000 hours could be lifetime...thru a couple owners....of a boat.

[Boracay]

One five hundreth of 33% of installed value.

Assuming 500 hours p.a. and an installed cost of $30 grand that would be $20 per hour, plus fuel.

[Chipg]

Ok, then an acceptable time frame, I guess I was trying to avoid someone that has had only 1 oil change from 100 hours of use.

[Chipg]

Originally Posted by Boracay

One five hundreth of 33% of installed value.

Assuming 500 hours p.a. and an installed cost of $30 grand that would be $20 per hour, plus fuel.

WOW! That sounds really high, so a guy with 100 hours has spent $2k maintaining it? Or a guy with 1,000 hours has spent $20k in maintenance?

Does your figure account for the cost of the engine over its life sapn?

I'm just looking for maintance figures.

[Chief Engineer]

What Kind of Diesel are you looking at?

That would be a determining factor in cost of operation.

[Chipg]

A 75-80hp non turbo perkins or yanmar.

Just looking for rough ball park estimates.

[Chief Engineer]

Ballpark Figure? $4-500 a year for normal maintainance...spring commisioning, winterizing, factor in a fried impeller.

Just going by hours......may be deceiving.....look at seasons of vessel use....

2000 hours could be 20 years.

Or you could compare 2000 hours X 50 mph= 100,000 miles

Lots of different ways to look at it.

[Stillraining]

Chip...I don't have much marine experience with diesels but more then most with land based ones.

We have a saying...."It costs more to start a diesel then it does to run one"

Translation...The costs associated with running a diesel are more pointed to how often it is used compared to how often it sits unused.

I Have several of them around here close to 25 years old with 10K hours on them that purr like kittens, burn next to zero oil and start within 1 or 2 reves that I can put on a job tomarrow with total confidance it there soundness..my boats Perkins had 2500 hours on it in 25 years and needed some dire attention and was not trustworthy at all.

What your asking would be way easier from say the commercial fishing industry or from a tug boat captain whom have good records over years of servive with high hour engines...unfortunately there is no bench mark for sailboats or in the recreation industry as a whole due to the haphazard nature and quirks of all the different owners out there...One owner took stellar care of the engine used it alot and the next owner of the same boat new diddly about it, used it rarly and so as long as it started they ran it...much the same as some treat their cars..it doesn't get service till it has an issue...not from lack of responsibility persay but a total lack of understanding.

As a fellow Pilot ...I can maybe sense your frustration in what I'm saying... but think of a C152 trainer used every day...Tons and tons of hours yet doesn't miss a beat and is meticusly serviced...That same 152 privately owned and rarely used seems to have far more issues and a resulting lower TBO then the trainer.


Hope this helps.

[Meridian]

All hypotheticals...
Yanmar 4jh series, 75 hp (turbo'd, though), 2000 hours of use
-Oil changes 6.5 ltrs every 100 hours (250 spec'd in manuel) roughly 130 ltrs oil@ $5 per liter figure $650 (conservative).
-20 OEM oil filters at $12 each $240
-7 OEM impellors (every 300 hrs) at $50 each $350
-1 OEM belt $60
-1 valve job by good mechanic (at 1000 hrs) $200
-1 radiator flush/ re-fill (when doing valves) $150

Total approx $1600 for 2,000 hrs of engine use, well under $1/hour.

NOTE...all figures are wild-ass guesstimates, but based on some experience.
Even if I'm off by 100% on the cost-of-goods, I went conservative on the intervals.
Obviously, major problems are not factored in. Nor are geographically-dependent items like annual de-commissioning/ re-commissioning due to cold weather (ick). If its that cold where you live, take up snow mobiling, not sailing.
Anyway, hope it helps
John

[Ram]

My actual costs on Yanmar ym30- oil $25 per 125 hours -oil filter $12 --belts 1 every 300 hours ,fuel filter 250 hours $8- I changed one water pump">raw water pump (early) 700 hours cost of $230 usd -
Flush both engines and changed coolent 300 hours at a cost of about $25 each time-nothing eles and this is on 2 engines

These engines are used a lot - 700 hours in 3.5 years -resting with no use 6 months of each year

[Boracay]

Just so we keep them in mind:-
Depreciation will run 6-12%
The money to buy was either borrowed or could have been earning 6-12%
Most will insure the engine as part of the boat, say 2%
Many boats are kept in marinas, the engine stays there too, say 8%.
And it would be wise to allow annual maintenance costs, say 7%

Just rough figures, or are all those stories about fixing boats in exotic locales just myths?

[cat man do]

Originally Posted by Meridian

All hypotheticals...
Yanmar 4jh series, 75 hp (turbo'd, though), 2000 hours of use
-Oil changes 6.5 ltrs every 100 hours (250 spec'd in manuel)

I have a pair of Cummins B3.3's at 65 hp (they do go out to 85hp in turbo)

Maintenance Intervals.
Turbocharged B3.3 engines require an oil change at 350-hour/3-month intervals, while naturally aspirated models can go 500 hours or 6 months between oil changes.

Cummins Southern Plains - B 3.3 Engine

[Chipg]

Thanks guys, appreciate the replies!

It'll be for a fairly new low hour well maintained engine, a live a board in warm climate that will be used on a regual basis, probably 200-300 hours a year.

Sounds like I can expect a 'rough' cost of $4-6 per hour to maintain it but if I can come in at $1 per hour that will be very nice! That's not bad at all, then another $4-5 an hour for fuel.

I'll be doing all the maintenance / oil changes myself. I have rebuilt countless engines over the years for cars I have restored and even a couple turbine aircraft engines so even a major failure of some type would be something I would attempt to repair myself.

Boracay, are you a CPA?

Thanks!
Chip

[David M]

I think there are too many variables to give anything other than a very rough estimate.