A good number of diesel authorities will tell you which diesel-powered motors will last a long time to come. I have acquaintances that run an 18 wheeler nationwide. They tell me that truckers can normally put over 200,000 miles on the tractor/trailer every year. So at an average of approximately 60 mph puts over 3300 hours per year on the engine. And if the truck is six years old there will be about 19,000 hours on the motor.
Marine diesel motors are manufactured to much closer tolerances than are gas engines. They will often deliver, if well taken care of, 15,000 hours of demanding performance before needing a major overhaul. In theory, a well taken care of diesel boat engine might endure your entire life span. Given that the customary pleasure cruiser runs only approximately 100 hours each year at most, the fifteen thousand hour diesel would likely last approximately one hundred fifty years. That should certainly be adequate!
So what is the reason that we boat owners get all worked up about boat engine hours? Once again, good question. I think it is really a boater thing. We boat owners are inclined to get worked up about even the little things.
Vessel engines are run in a totally different manner than tractor/trailer engines in a number of ways. We probably don't idle as much yet the vessel motors are constantly under a load while cruising. Having an engine under load places a little demand on it however if it's a diesel, that is a positive thing.
As you are thinking about buying a used boat with diesel engines, I always recommend taking oil specimens. The oil analysis will give you a complete understanding of the internal overall health of the marine engines. You will then be aware what you are purchasing and will confirm that the prior owner did without a doubt service the engines properly. Conversely, the regular marine gas motor runs for fifteen hundred hours prior to necessitating a significant overhaul. The quantity of hours that a marine engine will operate without problems is primarily based on the amount and quality of maintenance over the years.
The usual gasoline marine motor will work just fine for the first 1,000 hours. It is at this moment in time the marine engine will start to show signs of issues. If these problems are not addressed right away, they can turn out to be big issues quickly. Perhaps surprisingly, a vehicle engine could run basically twice as long (3,000 hours) as your boat gas engine. However, vessel engines work under the most horrible environments of salt air, wet bilges, stop and start actions, serious loads and quite often just total neglect. Not servicing a marine engine will definitely enable it to give up the ghost early.