Be careful...just read through the engine stuff and the guy is somewhat off from most conventional thinking...like letting diesels warm up for 30 minutes at the dock...or letting them cool down at idle for 20 minutes or running them 30 minutes a month instead of pickling/winterizing.
The danger, I think, in trying to make generalizations about engine operation is that engines for the most part of different from each other. Warm ups, cool downs, periods of full throttle running, etc. can vary considerably by the nature of the engine, how it is intended to be used, how it is actually used, and so forth.
As Rick pointed out, the operator's manual is always the place to start. If there was any general, applies-to-every-engine rule, that would be it.
After that, there can be variables.
When we bought our boat we were total novices at the care and feeding of marine diesels, specifically the two FL120s in our boat. All we had to do with the Cummins engine in the GB36 we chartered was not exceed x-rpm, cruise it at y-rpm, and let it warm up "for awhile" after we started it cold.
So we talked to the experts we coud find about our engines. This included the very reputable and experienced diesel shop that works on pretty much every commercial and recreational boat in Bellingham and some friends in the marine diesel manufacturing industry.
We asked them about warm ups and cool downs and cruise rpm and what kind of oil and so forth. And their answers were all consistent.
A warm up period was recommended as was a cool-down period. However with our engines the cool down was not critical and we were told that the time we spent idling from the marina entrance to our slip would do it anyway.
The advice we got for our engines with regards to periods of inactivity was to run them every four to six weeks if we could. Which we do if we don't actually take the boat out in that period of time. But...... not just to run them but to run them with a load to get them up to temperature and then keep them there for awhile.
Winterizing the engines is not a necessity here. Even people we know who don't use their boats at all from October to June don't winterize anything other than their boat's fresh water system if they so choose and we don't even do that anymore. Most everyone we know who doesn't use their boat all winter changes the oil after the last use in the fall but there are a few who don't do that, either.
So as with most things to do with boats, I think it's hard to impossible to come up with generalities that apply across the board. If Carey had asked the same questions of the diesel shop we did but about the 420hp turbocharged Cat in his boat, I daresay he would have gotten somewhat different advice.
I didn't look at the technical articles on the website. I looked at some of the maneuvering stuff and dinghy stuff and whatnot. And I thought it was good advice he was giving, albeit certainly not the ONLY way things could be done. More practical, I thought, that the so-broad-as-to-be-almost-useless generalities I read in Chapmans, a book I have found to be almost worthless except to a total newbie to boating who's at the very bottom of the learning curve. For them, it provides a good foundation I guess.
