best engine

[tjandoverguy]

what engine is best on fuel for a 30 to 35 ft sailboat

[Suijin]

Diesel. The actual size of the engine that is best suited (i.e. can most economically drive the boat at hull speed) is a function of the hull form, the boat's displacement, the prop size and pitch etc.

Most manufacturers (or reputable marine dealers who do installs) will give you a recommendation on what HP is a good match for your boat.

[denverd0n]

As a very rough rule of thumb, you should be in the neighborhood of two hp for every 1,000 lbs of displacement. So if it is, let's say, a 16,000 lbs boat then you probably want a diesel somewhere around 30-35 hp.

This is just a very rough estimate, though. As Suijin suggests, ask the manufacturer for their suggestion. If their suggestion varies widely from this, though, I would ask a lot of questions, and maybe get a second opinion.

Good luck.

[Island Time O25]

Also bear in mind that in that size range most marine diesels are marinized and re-branded versions of tractor or other industrial engines. So for example Beta and Universal are actually Kubota in disguise. Volvos are Perkins and Westerbekes are a mishmash of many different makes (which makes them more problematic for maintenance and repairs as told to me by a diesel mechanic with 40+ years of experience).

More important questions would be: -are there knowledgeable and not too expensive mechanics in my area should they be needed, -are parts readily available throughout my cruising grounds? -the prices for parts relative to other makers and/or alternative suppliers (i.e. tractor dealers)? - how easy would it be to service in my particular engine room situation. You may be lucky as I was in all of my boats in that there was good room (for a boat) to work on most of the issues and the engine make would not make a difference. But on other boats that may not be the case. So for those boats with poor side or aft access, all else being equal, Beta would be the best choice as they make all engine systems easily accessible forward, where most boats have the best access.

[GrowleyMonster]

My engine doesn't use ANY fuel. Well, kilowatts, actually. It is an electric motor.

Denver Don and Island Time hit the nail on the head for you. A diesel will be more economical and (as long as you feed it good clean fuel), more dependable. And Beta makes an excellent product, easy to care for, reasonably cheap. You could of course add heat exchanger, marine transmission, etc yourself to a salvaged tractor engine and save money, but only if your time is worth nothing at all and you are a pretty fair engineer. Beta puts a very nice package together for you, and you can have it shipped to you and instaall it yourself if you feel up to the task.