Westerbeke has nothing to gain by promoting the use of synthetic oils and therefore it becomes a liability to invest in the research to confidently advise that oil changes can be extended to certain intervals. I wouldn't expect a company like Westerbeke to give two shits about people wanting to extend the life of their engines if it meant they had to spend money to do the research. There has been enough research done by innovative engine manufactures like Volkswagen, Mercury, Cummins, BMW, Yanmar, Volvo and the like, that it is not even an option to use mineral oils in many of them. Synthetic oil manufacturers have published the results of all their tests which show that the use of synthetic oil has only positive effects in engine longevity, oil longevity, filter longevity and the overall efficiency of the engine. I know change is scary, but so is living in the past.
Sounds like an Amsoil commercial....
Synthetic gets expensive when you consider many marine diesels will run 15k hours+ on conventional oil without issue. They fail from many reasons other than the oil used. If it is less expensive due to longer change intervals why are the vast majority of trucking fleets still using Dino oil.?
I have numerous commercial marine customers with over 10k engine hours, and a few with 15k+, and they all run Rotella T or Delo conventional Dino oil.
Remember we are talking about sailboat AUX engines here... 10k hours on a sailboat, at 100 hours avg per year, means your engine lasts 100 years + using just conventional oil.
Also consider that "Million Mile Joe", a local guy here in Maine, drove a run of the mill Honda Accord 1,000,000 miles
on the original, un-rebuilt, engine and transmission using nothing but conventional oil & regular transmission fluid.. If a basic Honda accord can go 1,000,000 on conventional oil, is a synthetic really necessary.......?
1,000,000 MILES on regular Dinosaur oil in a run of the mill Honda!!!
How many folks do you know that run their cars to 100k or 200k let alone 1,000,0000 miles...? So why do we need synthetics if today's engines can go 1,000,000 miles on regular and inexpensive Dino oil? If we were to listen to the marketers of synthetics we'd all have failed engines by 50k..
Heck I don't even buy cars unless they have over 100k on the odometer and have never had a single oil related engine failure except for oil leaks on cars I owned that ran synthetics..
There are many other things you can do for your engine to get the most out of it that will do far more for its longevity than conventional vs. synthetic..
Most boaters would never even come close to the engine hours where a synthetic might
make a difference in longevity..