I am sure that I will get lots of differing opinions but I am interested to know which diesel engines are considered to be most reliable, require the least maintenance and are economical to operate? Also and maybe more important which engines should be avoided? I am also interested to know if fuel consumption has gone down significantly over the past say 10 to 15 years for a given engine size. For example does a 370 hp from 2000 burn significantly more fuel than a new 370 hp engine.
One last thing. Are there issues with buying a boat with an engine that is say 25 years old with relatively low hours if it has been well maintained?
I know I am asking for a lot of info.
Thanks for your thoughts on these issues.
Happy New Year!
David is spot on with his post.
I'll add this. Let's take the Cummins 6BTA 370. There are over 3 million "base engines" in world wide service across all industries. A marine 6B base engine
will last a good solid 6,000 hrs. in marine service before it gets a bit "tired". The engine can be rebuilt.
I'll also add that the vast majority of ALL marine service engines will NEVER see the total number of service hours the base engine
was designed for.
Why?? Here's a list of reasons in no particular order:
Marine age, no different than us humans aging !
Rust and corrosion from salt water drippings,spray immersions
Multiple owners who are clueless
Lack of rountine maintenance, NO not talking oil changes and filters,
lack of maintaining the salt water cooling side of the engine.
Weekly due diligence of the engine, checking ALL over.
Overheats, no alarms
Overloading the engine, no understanding of propping
Overloading the engine X 2
Broken serpentine belt, no alarm
Worn broken hose, no alarm
No alarms X 2
The "nut" behind the wheel
Failed alternator bearing, NO alarms.
Worn/busted raw water pump, NO alarms
Poorly designed exhaust system...BIG culprit !
I may have missed a few reasons!
Think about it. An average recreational season may be 125-150 hrs. of engine use. Multiply X 20 years, maybe 2500-3000 TOTAL hours.
Toss in 3 or 4 owners who start out "clueless" as owners.
What are the odds of the base engine
reaching 6,000 hrs. ???