I disagree that a marine engine
has a harder life than an automotive diesel
,i drive an old VW passat tdi, it has over 230000 miles on it,i live in minnesota
where it gets very cold,i live less than 4 miles from work so when i start my diesel
in the winter at anywhere from 20 degrees F above to 20 degrees F below zero the temperature gauge has barely started to rise when i shut it down again,even in the summer it dosnt get fully up to temp.In the summer the amount of dust i get on my dash is an indication of what the engine
has to breath(no dust at sea) I would think that my engine would love to be running at a constant rpm
around its max torque of 1900rpm fully warmed up and happy..I think a truck has a better life as it gets to be properly warmed up but car engines can have a horrible life and still last well.
Re the yanmar
,a friend of mine bought a 2GM20
as a running takeout with 8500hrs on it,it was in a Cat and the other engine had failed,the boat motored back to Florida
from the Bahamas
on this engine and then was repowered,my friend put this engine in a 37ft ketch
in Bellhaven,NC and then motored it several thousand miles to Duluth MN with no issues and no excessive oil
burn etc,its a nice engine so 10000 seems quite realistic.