Diesel vs Gas 400DA?

[BVasily]

After 10+ great years with a 330DA I am looking to move up to a 400DA. Two boats of interest local to me (Canada ... although certainly will look at fresh water US) ... one diesel the other gas. about $20K price difference. I was told by a broker that fuel usage per hour is similar for both and that the diesel will simply run a bit faster on the water so there is a marginal economic gain??? Any enlightenment from this group would be helpful.

 

[hottoddie]

Gas engines in 400DA are marginal but depending on how you use the boat may be adequate. The gas motors will burn about 25% more fuel per hour but diesel usually costs more at least around here. Do you do your own maintenance? Maintenance is more difficult and costly on the diesels I don't care what anyone says. Repower costs are at least double on a diesel boat. If your use is less than 100 hours per year and you don't mind cruising at 18 knots vs 22 knots then the gas is a better choice IMHO.

 

[northern]

If you go fast gas is way more based on diesel. At 18 knots we burn 55 GPH at 6 knots we burn 6 GPH. I can fix a gas engine I can not fix a diesel engine. If you go with diesel you will be able to put in a oil heating system with gas you need to run your generator to stay warm.

 

[fwebster]

Bob,

I'll start with "Your Broker is Wrong!"................

The diesel boat is faster, but it also burns a lot less fuel. A 7.4L Mercruiser is going to burn about 30 gph at cruise. Most of us who have the Cat diesels cruise them at about 2200-2250 rpm which gets their fuel burn down to about 18 gph. The other thing is that you have the typical riser manifold checking/replacement every 5 years on the Mercruiser. The Cat risers are bronze or stainless and just don't rust out. The only real maintenance costs on the 3116/3126 are for oil and filter changes and impellers every 200-300 hours. Since the diesels hold 26 quarts of oil, the oil change cost will be higher than with gas engines. Repowering a diesel boat just isn't a real consideration for a pleasure boater because 1.)the engines don't die an early death from water ingestion from failed risers and 2.) if they are cared for and not overloaded, they run for literally thousands of hours. I have a friend in Florida that runs a charter boat and he has 16,000+ hours on his Caterpillars with no major repairs.

As far as the maintenance being more difficult and more expensive is concerned....if you do your own routine maintenance, that is an incorrect statement. Regular things like oil changes, fuel filter changes, transmission fluid changes, impeller changes, etc. are easier. There are some service items you cannot do because they require expensive proprietary tools, but those items only occur at about 2000 intervals. On the other hand, if you have to get a diesel mechanic to the boat to do routine maintenance, the diesels will cost more. I had a boat with 7.4's for 9 years, and I've had the 450DA for 16 years now and I am spending far less money keeping the diesels maintained and running than I did on the old 390EC.

I think the primary factor to consider is the future depreciation in the new boat. A diesel boat will depreciate down to a point, but then will hold its value while a gas boat continues to go down in value. If you are looking at 400DA's, then the value is about fully depreciated, and as long as you maintain it, its value will hold. That isn't the case with a gas boat. Once they get past about 15 years, buyers will discount them by enough cover repowering costs because they know that very soon the engines will need overhauling or replacement.

The 400DA is a great boat .....have fun shopping!

 

[grayzone]

I know the 380 is a little lighter but I found these ulr's really helpful when making our choice.


I find @ 25-26 mpg we burn 32 US gals @ 3300-3500 rpm.

I do all my own work so gas was a good fit for us.

we put on about 100 hrs a year

http://www.boattest.com/Partners/Partner-Main.aspx?lp_id=32&t=BOAT-TEST&Videoid=338&p=0&s=


http://clubsearay.com/archive/index.php/t-7142.html

 

[boltman]

I'd look at the diesel boat ,more power,more torque and Frank is correct ,gas engine will burn twice as much fuel then diesels .



Sent from my Nexus 7 using Tapatalk

 

[Carver370]

All of this is good info, however what Frank mentioned about the risers and manifolds really doesn't pertain to freshwater use. Simply don't need to.

The diesel boat will feel better when running for certain but if that doesn't make a difference to you and 20k does, you will never burn enough fuel for the economy to matter.

 

[HUMPH]

No question as far as I am concerned. Better handling, better fuel economy, less maintenance, and better resale.

 

[Boat Guy]

.... I was told by a broker that fuel usage per hour is similar for both and that the diesel will simply run a bit faster on the water so there is a marginal economic gain??? Any enlightenment from this group would be helpful.

Whether to go gas or diesel is personal preference. But, I don't agree with what your broker is telling you. So, I'm posting this for you. In my experience, you will get much better economy with the Cats.

I know that you can find gas boats on the market cheaper. If the difference is an issue for you, I caution you about purchasing this boat. The reason I say that is, I see a lot of gas boats sit at the docks because the owner doesn't want to spend the money to run her. They are basically slip boats. I'm not talking about the 400da specifically when I say this. I see this talking to owners that have boats that are relatively large and gas powered.

I don't know about maintenance costs comparisons. But, if you have any mechanical ability, I think you will find the Cats as realtivley easy to maintain and diagnose. I like the simplicity of the diesels.

Also, I will bring up another issue. Personally, I feel a diesel boat is safer. So, that was a strong consideration for me.

Good luck in your search.

 

[ttmott]

To add to the above comments; The diesel is a superior power plant for these size boats. You put a diesel powered 400DA in gear and it moves with authority and predictability; gasoline will definitely require coaxing with some throttle. The diesel engine's torque at idle just cannot be replicated with the gasoline powered engines. Insurance is cheaper. Your options for electrical modifications (inverters, chargers, etc) are better suited in a diesel boat as these can be installed in the engine room whereas in a gasoline boat everything must be explosion proof in the engine room. All of the 400DA 3116 and 3126 diesels have mechanical injection which is simple and reliable; if your maintenance is current it is highly unlikely you will ever have a problem.

 

[peterkvs]

I looked at both gas and diesel 400DAs. I settled on a diesel boat and after bargaining got it down to the same price as the gas boat, so it was a no brainier. The diesel boat out performed the gas boat is every way. There is no comparison. The fuel usage is half that of gas and the maneuverability of the diesel boat is fantastic. If you plan on spending time on the hook with the generator running there are significant advantages to diesel. First the CO threat is far less and second you are not sitting on 300 gallons of explosive gasoline while you are sleeping and your genset is running away. You can expect many thousands of hours from the diesels if you maintain them versus one thousand for the gasses. Same goes for genset. Great thing about the 400DA is the cat 3116 are super simple engines. Easy to maintain, they start and run like clocks and not hard to diagnose what's going on if you do have an issue, there is a lot of oil and coolant in them and when I bought mine I had no idea what the service history was, so I did everything. That was quite a bit of work and money, but now I know what's going on and I feel very confident about the motors.

Good luck,

Pete.

 

[Gofirstclass]

One thing that has been touched upon is the superior handling of diesels, but the reason has not been stated. Quite simply, the diesels are going to have bigger props. When you put those big props in gear, coupled with the higher torque of the diesels, that's where you get the better handling.

With my boat that weighs around 58,000 pounds when it's loaded, when I'm maneuvering around docks it takes just a light touch with the shifters to get the boat to respond. Those big wheels move a LOT of water so I think you'd spend a lot more time in neutral and less time in gear.

In a boat that size, if you plan to use it 100 hours or more a year, it would be a mistake not to go with the diesels. If you only put around 50 hours a year on your boat, you'll never recoup the additional cost of the diesels with the fuel savings.

 

[Aerobaticflyer]

You do not say the year boat you are considering so I will speak to my experience. My 2005 390DA (same boat as a 400DA essentially) is diesel and when I bought it I didn't consider gas. I run 100 hours a year and plan to keep it quite some time so wanted the durability and life span of diesels. Consider a gas 340DA has the same 8.1's as the much heavier 400DA and you get the idea pertaining to performance.

I have no regrets. Best of luck with your decision.

 

[K-DUB]

I specifically looked for a gas 400DA. I had always thought I wanted a diesel boat until I watched all my buddies catastrophic engine failures on their big diesels. Manns, Cats, Detroits, one at 300 hours, others at 600-700. To the tune of 20-30k to fix. These are all open checkbook boats. Larger than 40, but diesel all the same. I boat 100 or less hours a year having only a 4 month season. The fuel economy was not enough to pay for itself. As far as performance I run at 26mph around 33-3400rpm. Many instances I have had 14 passengers without even batting any eye. I went for the 1998 because that’s when they bumped the HP to 380 on the Mercs. A gas DA will plane faster weighing much less in the stern. I have nothing against diesel boats. Just not something I wanted to deal with. The only thing don’t have that the diesels do is the response around the docks. It’s not a showstopper though. I have no regrets with my boat. I would not be afraid of a gas 40.

 

[Timeflys]

I noticed your location..do you plan on keeping the boat on the Rideau?? If so, I'd probably stick with gas. Another point, if you're going to be doing a lot of locking through, is the smell of diesel exhaust in a confined area going to bother you?. Food for thought...

 

[Bryank]

I have a similar boat (2001 410DA) with gas engines. All the good points stated about diesel are true and I am sure my boat would be more efficient and handle better with diesels. That said, the 8.1 gas engines are perfectly adequate for getting on plane and maneuvering around the docks. I have absolutely no complaints in either area. That said, my fuel economy sucks. But if I'm worried about that, I should find a different hobby!

 

[mistercomputerman]

I have a gasser that I repowered with 8.1s

Run at 3400/23knots/.7 mpg.
Last year ran about 1500 miles or so.

I am not unhappy with the boat/engines, but, had I been as knowledgeable when I purchased the boat as I am now and had I known that I would use the boat on trips as much as I have, I would have probably purchased diesels.

 

[Alex F]

Considering your location, I think it boils down to major factors like:
- How many hours and miles you put every season, fuel availability (not all marinas carry diesel)?
- How long are you planning to keep the boat?
- What is most common power package and sells better in your area for that size/model boat (this will help you understand the resale side of it)?
- In regards to resale, do a simple math. For example, if you buy a boat with 500-700hrs that's 10-12y/o now, you plan on keeping her for 7-10 years and plan on putting about 100hrs per season. When it's time to sell her (fast forwarding 7-10yrs), you're selling roughly 20yrs old boat with 1500-1700hrs. I would do a market analyses and compare the difference between the selling price, availability and how long it takes to sell one of 20y/o 1500-2000hrs 400DA gas vs. diesel.

The point here is that what makes perfect sense fuel savings wise, maintenance wise, etc., etc., doesn't necessary cover the whole picture. I'm willing to bet that in most cases when buyers look at 20y/o 40'er with gas engines in the range of 1500-2000hrs, they think that the engines are approaching the end of their life and may need major work very soon, which sometimes makes most sense just replacing them with new set. On the other hand, when the buyers look at 20 y/o 40'er with diesels that have 2,000hrs, they (those that have any clue) would think that it's very normal usage and if properly maintained these engines will have plenty of life left on them (another good 10 years).

Do a comparison on the maintenance cost gas vs. diesel. Major ticket items on a diesel like aftercoolers, heat exchangers, valve lash is what cost big bucks. All other maintenance items are very reasonable. Make sure not to overlook having reputable service withing reasonable distance, b/c if a good shop is 500 miles away, this can be a deciding factor.

Hope this helps.

Good luck.

 

[LMBoat]

I do not know of any diesel boat owners that wished they had gas.

 

[hottoddie]

I do not know of any diesel boat owners that wished they had gas.

Off the top of my head I know 2. Both are 35 ft sport fisherman boats (different makes). Both have 3208TA Cats and have had issues the past couple of years that have costs them thousands. Both wish they had 454's that they could fix themselves for short money.