Diesel Vs Gasoline

[timangiel]

Are there any opinions as to which is more desireable, diesel or gas engines? Are there any advantages to one verses the other such as reliability, cost of ownership, ease of maintenance...ect. Thanks.

[pigslo]

Gasoline engines have the potential of blowing up if the fumes are not vented properly. That would be the bigest reason most sailboats have diesel.

[camaraderie]

Diesel only! Gas is hard to sell and cheap to buy as no one wants them. Diesels run forever and are easy to fix and won't explode if heavier than air fumes gather in the bilge.

[Canibul]

Not sure, but I think I read that diesel fuel is more stable for storage as well. Not as volatile, so the good stuff doesnt evaporate out of it as fast or something.

Doesnt everyone store gasoline onboard for their outboard, anyhow?

[Rockter]

Diesel is where it's at.... more range, virtually no explosive risk, more energy in the fuel, the engine extracts more of that energy, no need to maintain a spark, lasts far longer. Once provoked, it will cause a massive fire, but it needs some provocation.

I have a wee gas storage box right forward. I carry the volatile stuff there.

[Faster]

All the above posts have it right - diesel fuel is safer to store, diesel engines have longer range and are less prone to problems that gas engines have with their moisture-sensitive ignition systems (especially since most gas engines in used boats are at the 25+ year old level of technology for fuel delivery, carburation and ignition). Market forces are also a big factor in the popularity of diesel auxillaries.

That said, though, it's a bit of an irony that the way we use our diesel engines is really not a great application for a diesel: short runs at low loads followed by (hopefully) long periods of shut down.
Diesels like to run hard and run long (a generator for a small plant, remote camp or village is an excellent application of a diesel engine - as are tugs, trawlers etc.) However the other safety and market issues pretty much dictate diesel engines in sailboats.

There are a great many decent sailboats on the market with gas engines. Their disadvantage is primarily the safety issue, since most can be fitted with modern ignition systems less prone to moisture problems. What they do provide is plenty of power, reduced noise levels, and smooth operation. (Compare a 28 foot sailboat with a 1 cyl diesel - can you say "vibration"?-to the same model with a Atomic 4). Prices of gas powered sailboats are, of course, much lower.

Since a prevailing theme in the boat buying posts seems to be people looking for the most boat for the least dollar, many on a limited budget will get much more boat if they are able to find (and live with) a gas powered version. Granted extra care must be taken to ensure the engine is in good condition and has been well maintained, and fueling practices and storage need thought and care.

So though without a doubt a diesel powered boat is a better long-term purchase, those on strictly limited budgets might do better (in terms of boat for the bucks) if they considered gas powered alternatives. If you find a really well maintained and equipped gas powered boat - preferably FWC - there's good odds that the owner looked after the engine as well. In addition, support for the venerable A-4s is pretty good again, unlike 10 or 12 years ago.

In short, there are lots of reasons why diesels rule - but for some, there may be a good reason to look at the other side.

[Rockter]

Certainly if the gasoline is ventilated, it's practical.

But if it's not, or if a fuel line perishes, or if there is a fuel leak, or if the tank weeps.... oh man, it's a bomb, and you are sitting on it.

Take some diesel one day, and try to set it on fire. It won't wear it, unless you have a rag in it. Try it with some gasoline and.... woof!

[SteveCox]

Do any of you who are so adamant about the dangers of gasoline use propane on your diesel boats? Propane is just as dangerous if not more so than gasoline yet people who advocate a diesel for safety seem to have no problem with propane. Yes gas can be dangerous under just the right set of circumstances but gasoline has been used for decades for auxilary propulsion with very few catastrophic problems. Use your bilge blower, use your MKI nose before hitting the start button and you won't have any problems. Faster is right on the mark. If you are mechanically inclined a gas engine can be a real money saver when buying a boat. While gasoline is more expensive than diesel I can buy a lot of gasoline for the several thousand dollar difference between the same boat with an atomic four versus a diesel.
Having said all that, my new boat has a diesel. Why? Because of all the other advantages a diesel has over a gas engine as other posters mentioned. If you are going to keep a boat long term I think a diesel is the best choice. I just don't think that safety is a good reason to choose diesel over gas given the tremendous price difference.

[cardiacpaul]

While diesel has obvious advantages, please consider that the A4 was installed in over 40,000 boats.

I'm not going to take up the cause for gas engines here, but diesels are much more expensive to rebuild (yes, I know the hours to rebuild is higher as well) And the availability of parts is limited.
I just tuned up my A4 two weeks ago, Plugs, points, wires, cap, condensor and coil. total outlay. 53.00 all parts from NAPA

I'd hate to frighten a person off a boat just because it has a gas engine. As far as the "venting" issues... When the boat had her gas engine installed, the venting was proper for it.
(owner of 2 diesels and one A4)

[Rockter]

If the tankage is external, as propane is, then maybe. But 50 gallons of gasoline below your feet, and a fuel that evaporates and mixes with air the moment it gets a chance.?... not for me.

I have got a few motorcycles, and when fuelled at the start of winter, and left through the winter, the fuel level in the tanks always drops, and noticeably. The tanks have a wee pin hole breather, yet the level drops.

Next time you fuel the car in the sun, mess with the shadows to see the shimmer next to the fuel entry. Notice how it descends.

Mess a little with it one day in the open air, to see how aggressive and unforgiving it is, and imagine it lurking in the bilge.

End of sermon.