Gas engine or diesel?

What is it that makes a motor yacht, a motor yacht? The “motor” or engine of course! And when it comes to what puts the power, in a powerboat, the age old question is: diesel or gasoline?

The size of your boat is an important factor in the choice of diesel vs gas. Generally speaking diesel engines are only found on boats of 40 feet or more, and with a gross weight of more than 18,000 pounds. This is because once you reach that size range, gasoline engines lack the torque of a diesel engine.

Sure you will find gas powered engines on boats over 35 feet, but such a motor yacht may be underpowered and use much more gas than it should. The larger the boat the better off you are with the performance and fuel economy of diesel engines. Because of their increased fuel economy diesel engines will not only save you money, but they will extend your time on the water, and your cruising distances.

Head to Head Comparison

If size is not the determining factor, and you are choosing between having diesel or gas engines installed on your boat, of course you will need to consider the relative costs of each option.

If a boat is being built for you, diesel engines will likely add a lot more to the upfront purchase price, than would gasoline engines. But, a diesel powered boat will likely save you money in the long run. Diesel marine engines tend to be easier to maintain, they tend to last longer, and they will help your yacht hold its value you longer, when it comes time to sell. Also, while the prices of marine fuel fluctuate greatly, generally speaking, marine diesel fuel tends to cost less than marine gasoline.

A Marine Diesel

A Marine Diesel

Now, all this is not to say that gasoline engines do not have some advantages over marine diesel engines. For one, a marine gasoline engine will run much quieter than a diesel of similar size and power. Another thing, unless your diesel powered vessel has an underwater exhaust system, the fumes from gasoline engines are not nearly as noxious as from diesel engines.

While routine maintenance of a diesel engine is generally less than a gasoline engine, and they tend to last much longer than gasoline engines, if something does go wrong requiring a rebuild or overhaul, you can expect to pay as much as three times more for that kind of repair job on a diesel engine.

.Other Things to Consider: Gas Vs Diesel

Of course, there are some other things to think about when considering a choice between gasoline or diesel engines, such as where you are going to use your boat, and how fast do you want to go. But remember, you really only have a choice between the two types of engines on boats that are 45 feet or under. Bigger boats than that, really need the additional torque and horsepower of a diesel. Then again, if you want to go really fast in a boat under 45ft, you also would probably prefer a diesel.

cost of marine diesel

Size, engineering and power requirements aside, it really comes down to evaluating the potential benefits versus the cost, maintenance, longevity, resale value and performance of each platform weighed against the way you intend to use your boat.

4 Stroke marine gas engine


Operating a motor yacht can be costly. You can reduce your expenses, and avoid costly repairs by keeping her well maintained. On Demand yachting from FYM can help. If you would like to learn more, or if you have any questions or comments about this blog post, do not hesitate to contact our Yacht Management specialists, or call us at (954) 900-9968.