Is there a considerable difference in fuel economy between gas and diesel inboards?

Question

I'm looking at 31' Tiara. It displaces about 6 tons.

Answer 1

The cost of a diesel boat is more the resale is more the fuel consumption for diesel is less> The power is more>

If it a larger boat diesels the only way to go> Gas at the marina is more than diesel>As gas is  87 octane>

Answer 2

depends on your use most yamar type diesels are low rpm and have a heavy duty flywheel that crates alot a enertia. Great for sail and motor sailors. if its a power boat performance is usually better with the gas engine...but not  always. If your looking for a super fuel efficient larger boat check out George Beuhlers book The Troller Yacht Book.

better yet heres the link read the abreviated version.

http://dieselducks.com/Concept.html

Answer 3

The Tiara's are planing hull boats that take some serious power, but if your only going to put say 150 hours on it this year, you'll be paying a premium for fuel and maintence.  The gas engines will do just fine, and you will notice a differance at the end of the year, in total cost, in favor of gas.  It's just my opinion!  

Answer 4

Yes.  For the same power output, the Diesel will use about a quarter less fuel.  Unfortunately, Diesel fuel is about a quarter more expensive than gasoline.

Answer 5

tremendous difference.   Figure a diesel burns about 1 gal/hour for each 15 hp developed,  not the engine rating, but the actual power output.  A well-tuned 4 cycle gas engine may get to 1 1/2 gal/hour for similar conditions.     But,,  a diesel will develop a lot more torque at lower RPM and with the correct prop, may run a considerably lower RPM for a given speed.  Overall figure 1/3 better economy. Diesel is more bucks nowadays, but you're getting more energy per gallon and the engines are inherently more efficient, and by the way, will typically last 5,000 hrs or more between overhauls, compared to maybe 1,000 or less for typical gas powerboat engines.   That's why diesels are more expensive but definitely the way to go.

and if that doesn't float your boat, keep in mind that gasoline fumes in the bilge, can explode if not properly ventilated,  while diesel is much, much safer.