Diesel or Gas?

J

jmeirhofer

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I am sure this has been hashed out before but I will ask again anyway if even for conversations sake.

I am looking at two identical 39' aft cabin boats. One is diesel and the other gas. There diesel is $95k more. Is it really worth the extra $95k? I do understand the safety advantages of the diesel over the gas model.

Anyway, let the debate/comments begin. I would be interested in hearing any and all.
 
Yeah, it's been heard several times. I went through it in the early 70's when I was going to buy a new car.
I remember one of the equations was: You'd have to own the car for 700,000 miles before you'd get the difference to pay for itself. But that was in a Car.

Now I'm older, had several Diesel pickups, etc, I sure like Diesel.

In your case, you gotta look at what you can pay, what the re-sale is going to be. In the end it comes back down to your Decision.

In my place if I were looking at two different 25' boats, one was a diesel, and several thousand more, I'd get the Gasser without hesitation.

My only complaint with the Diesels was the short life of the Ancillary parts. The Diesels shook the water pump's etc apart.

When I had boats, I never thought the cost of Diesel was too much comparatively. It's so much safer and easier to handle than Gas for a guy who does his own repairs.
 
Safety is an overplayed hand, IMHO. Yes, there are a few gas explosions every year. Invariably operator error and a statistical anomaly, given the millions of fill ups that happen annually.

I have gas in my 39 footer. I do 150 hours a year on the boat, give or take. At that rate, It would take the lifetime of the motor to save the $ difference between gas and diesels. In my case, the difference was $75K. Given that the fuel prices are about even now, and in my boat gas gets .5 MPG and diesels get 1 MPG, cruise at 20 MPH. So save 20 gallons per hour at $4 per gallon = $80 per hour. Round $75K to $80K and you have 1000 hours before the difference is made up.

Even at the rate I boat, which seems to be on the heavy side, that is 6.5 years of 150 hours per year.

If you boat like the majority of people, say in the 100 hour range, it is 10 years.

When I reach 1000 hours (I am at 520 already), the gassers will probably be needing replacement and I MAY replace with Diesels, depending on the difference in price.
 
If you have to try and do the math between saving money with gas vs diesel then you have never experienced diesel torque.

Not sure 95K is a reasonable difference in this market but personally once you go diesel you rarely go back,

One doesn't buy a Ferrari to save money...
 
I repowered a 40 foot Mainship about 4 seasons ago with gas engines. At the time I didn't know much about larger boats. I have been kicking myself over the decission ever since. When it comes to resale the diesels vs gas debate isn't a debate the same boat in diesel will always bring bigger dollars. Most if not all diesels will outlast gas motors. There is a safety issue which I don't think is minor again diesel's win hands down. If you can afford the boat with diesels and everything else is equal between the two go with the diesel boat. I would recommend an engine survey and then try negotiating the price down assuming the engines are in good shape. In this market I think you will be surprised how far a little price negotiations will go.
Bill
 
Imho, at 39 ft, you are on the upper ( size ) edge of where a gas engine might be used. Diesels are much more desirable the larger the boat.

If it were a smaller boat ( say, 31 to 35 ft ) I'd say flip a coin. But at 39ft, I'd go w/ diesel, for reliability. Will the gas engines do it? Sure. So would outboards, but I do not think I would recommend them, either.

As far a mileage is concerned, in this "new age" fuel is generally priced by the BTU, so I doubt there would be a big difference in fuel cost. But one gal of diesel will carry you further, so the diesel, w/ the same size fuel tanks should carry you further. Plus there is very little risk of explosion. ( It uses fuel, therefore it can burn. ). The initial engine cost is greater, and engine maintenance is likely more expensive, but the more robust engine should require less major service than the gas engines.

If you can afford it, get the diesel. ( and as stated above, negotiate HARD and get a better price. )
 
My diesel fuel is about 20% less than gas. My range is almost double and that is worth a lot to me.
I just like them and will probably never own a gas boat again.
 
And with Diesel you dont have to worry about the Alcohol in the fuel problem.
 
In my case, with a 26' Campion Toba, I have gas. I was always told...go diesel- life of engines longer , fuel burn or distance better...etc. BUT, you know...I'm glad I've got a gas engine. I have a Mercruiser 5.7, so basically a 350 chevy engine....the type of engine I used to work on and were very popular when I was a teenager! I can burn 7 to 8 gallons an hour opened right up, sure, but I don't...I enjoy the time traveling...do a leisurly 7 knots which cuts down my gas consumption by more than half. If I blow the motor tomorrow....no worries...I can replace the engine for under $4000....easily! AND, do the work myself...which in turn will save me more money. I can maintain, replace parts...tune....do whatever it takes to keep the engine in tip top shape, and for a lot less money than a diesel. There are advantages to diesels....don't get me wrong. But for the cost of a rebuilt or new diesel engine, I can burn a LOT of gas, go through a couple of engines and still have money in the bank! hehehe

Safety? As with any combustible element care has to be taken. Properly done, there isn't an issue with gas....only an issue if not handled properly.

Just my two cents worth!!!
 
I can burn 60 gallons an hour at WOT. At 39 feet with an aft cabin you will probably have a similar burn rate. Sure I can putt around at 5 to 6 knots and burn 3 gallons an hour but I would have been way ahead of the game if at the time of the repower I would have installed diesels over modern 8.1L HO's.
Then as another stated there is the whole Ethanol issue that come along with gas boats.
Bill
 
The ethanol issue is a valid point. But on my last trip on the intercoastal no one on the water was selling ethanol, this is not the issue it used to be. I think you need to actually run the boat with diesel and with gas to make the choice. If you break it down to financials you would go gas but if you look at handling and preformance I think you would go with diesels.
 
Ethanol is might not be an issue yet, but one of these days it will.
It is getting harder and harder to find ethanol free stations on land.
So far, no ethanol at the docks over here in S.W. La. yet.
 
If you're looking at new boats, I can believe there is a $95 difference for twin diesel. If used, the difference shouldn't be as great. If you're looking at used, I'd try to negotiate that price difference down to $40-$50 due to current market conditions.
 
quote:
Originally posted by PJ

The ethanol issue is a valid point. But on my last trip on the intercoastal no one on the water was selling ethanol, this is not the issue it used to be. I think you need to actually run the boat with diesel and with gas to make the choice. If you break it down to financials you would go gas but if you look at handling and preformance I think you would go with diesels.

Click to expand...

Did you miss New Jersey on your trip? There is not a single gas pump that isn't Ethanol?
If you did pass NJ I wouldn't blame you.
Bill
 
It would be easier to answer if you could tell us more about the two boats. Are they both new? If not, what are the engines and how many hours? Are there other equipment differences? Condition? Secondly, how will you use the boat?

I notice you are in California. Are you going to be primarily dawdling around the Delta, or doing long runs off shore, and realistically how many hours a year? As noted before, if you are going to put about the average recreational user hours on the boat, say 100, and just putting around inland waterways, it will take a long tie to make up the difference. Yes, diesels get higher resale value in general, because they start out way more expensive. I agree 39 feet is getting up there at the cusp, but not past it. There is an excellent discussion about gas versus diesel on David Pascoe's web sites, and I would really recommend his book "Mid sized power boats" as well.

George
Hatteras 56MY
Boston Whaler 130 Sport
 
If you are doing the "math" , don't forget the RESALE issue.

That diesel boat will not only sell for more $, but will sell FASTER.

But it's MORE than math.
Also, the published dry weight of a boat is generally far less than the actual OPTIONED OUT and loaded weight. For my size, 33' you can go either way but there are additional considerations that don't fit into any "math" decision.

Something not mentioned in all the valid points above is your most efficient cruising speed.

With gas 454's our most efficient cruise was 14.5-15.5 knots at .72 nmpg (veirified by flowscans)

With the Yanmars (no flowscans) based on fuel consumption data and actual fuel usage, our best cruising speed is 20 - 22 kts at 1.28 nmpg.

The additional torque creates additional lift and gets our a$$ end out of the water. We run more efficiently and can cruise farther.

The obvious is the extended range.

What's not obvious is that we can comfortably and efficiently cover more ground in a day than before.

This makes a run to Key West about 7-8 hours as compared to 2 days plus a fuel stop on the way.

For our application, that additional 5, 6, 7 kts per hour means 24 more n-miles covered on a 4 hour trip.

While the journey is the reward, the reality is we can do more on a day trip or two than ever before.

Another item not mentioned is soemthing important to most boaters out on the water.

RELIABILITY

Given clean fuel and enough battery power to crank, all other things being equal, the non common rail diesel will get you home.

There isn't a lot of electronics, sensors and connections to worry about operating in a harsh marine environment.

So there's two items that you cannot work into the "math" equation.

Add the above items plus the resale, safety, reliability, efficiency and YES lower O&M costs that don't fit into the math equation and the decision is easier.

Been there and done that!

RWS
 
quote:
Originally posted by The Other Gary

My diesel fuel is about 20% less than gas. My range is almost double and that is worth a lot to me.
Click to expand...


+1

Bob
 
We really do need a lot more info on the boats and how you will use it. If it will be a 6 knot floating delta condo then gas is fine. If you plan a lot of distance cruising then fuel costs become an issue because you will start to calculate the cost of every trip in advance. While you are unlikely to ever save enough to justify the expense of diesels after you own the boat the incremental cost of each trip becomes the important factor.

Diesel storage is less problematic than ethanol gas so if you wont use much fuel diesel will cause less worry on that front. Ten year old diesel will run just fine at lower HP levels where the cetane rating may not matter much.

Having said all that I would always choose diesels, I’ve had many gas and several diesel boats and just prefer the diesels. I prefer inline six diesel to gas V8s because aces is usually better.

IMO nobody has ever said they wish their boat has gas instead of diesel but the reverse is frequently true.
 
quote:
Originally posted by pdecat

IMO nobody has ever said they wish their boat has gas instead of diesel but the reverse is frequently true.

Click to expand...


Unless you need to repair or replace them..... hehehe.
 
Without knowing how you use your boat and how many hrs per year, the question can't be answered.
 
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