Diesel engines are the most common power source in marine usage, but all of the definitions and values given are equally applicable to other types of engines, including outboard motors, gasoline inboards, sterndrives, gas turbines and others. The new Jeanneau Leader 36 is offered with twin Volvo diesels in either 260 or 300 hp, or twin MerCruiser 5.7-liter 300-hp gasoline engines. But, in the size range of about 35 to 45 feet there are still plenty of gasoline V-8 engines that can generate enough power to get these boats up and running. A pod drive is a system in which the propeller units extend down … If you’re curious to know what the largest engine you can legally put on your boat is, try this calculator. Today I would argue that the maintenance cost differential between gas and diesels is really not that significant. They all have things like cooling system anodes, engine coolant, and water pump impellers that will need replacing periodically. The Crusader engine was removed from the boat and rebuilt on the bench in a shop; the Caterpillar rebuilt in place in the boat. You can travel at reduced speed on one engine for most of your voyage, maybe even alternating engines. I would argue that historically there is truth to that. Photo courtesy of Jeanneau. Photo courtesy of Yanmar. boat will always sell much more quickly, and will nearly always command a higher selling price. Beyond about 45 feet, you’ll really only have one choice, and that will be diesel. The shape of the backside of a boat, or stern, comes into play in … These are powered by diesel or gasoline and are available in single or twin engines. Two reasons for this are lower initial cost and less space dedicated to mechanicals, leaving more room for things like stowage and tankage. The Stern. It’s all about balancing efficiency and reliability. I’m not about to say which is better in terms of aesthetics, but I can offer observations of a more logical nature—assuming logic has any role to play in spec’ing out a boat with well over 2,000 horsepower hanging off the transom. If you can’t afford a new engine, think about reworking/upgrading your prop (see How to change a propeller). The Life Expectancy of the Marine Engine The average marine gasoline engine runs for 1,500 hours before needing a major overhaul. During a race, excessive saltwater ingestion on an Unlimited Hydroplane will almost instantly reduce engine output due… Suffice it to say that for the average boater, the difference in efficiency is probably not going to be a major consideration, especially at today’s fuel prices. In the smaller boat sizes, price points are critical and extremely competitive. . A test captain for Cobalt Boats recently describedÂ, the difference between their gasoline-powered and diesel-powered engine offerings on their new, “The gasoline version of this boat certainly has adequate power to get it up on plane and running nicely, but the diesel version is much snappier, gets on plane more quickly, and just feels more responsive.”, that this experience is not unique to the new Cobalt. When I asked various engineers and boat designers to … . Logic argues that the more parts there are, the more likely it is that something will go awry. If you figure an annual engine run-time of 100 hours (about average for recreational powerboaters in the US) the difference there would be about 240 gallons of fuel. Once you get over about 45 feet, displacement weight really starts to dictate the power requirements, and diesels win out in terms of the torque and horsepower available to get these larger boats up and running. Modern gasoline engines are all computer-controlled today, as are most diesels of any size in the propulsion-engine realm. Excess noise on board when you're underway really detract. When I asked him by how much, he was quick to say $20,000 to $30,000, matching what I had learned in my research using the NADA Guides. These boats are pushed hard without much regard to longevity; speed to the fishing grounds and, For the average diesel-fueled sport-cruiser, running conditions will undoubtedly be less strenuous. Spirit of Australia, max speed – 317 MPH. A driveshaft runs from the engine to the outside of the boat where it connects to a propeller. The way that power is created and delivered is very similar to how a car engine works. If you're in boat-buying mode and can't decide between gasoline and diesel, here are some pointers.