"So my brother-n-law recently visited and was asking some interesting questions about some of the techniques I use. He works at a lumber mill in Oregon, specifically he is a mill wright. So he professionally does maintenance on heavy duty machinery. He is not an apprentice, he is a fully certified mill wright. A lot of his questions center around diesels, but overlap to gasoline.
1) Grille blocks, engine heating in the summer, engine insulation. He claims that higher temperatures for longer times is reducing the lifetime of the engine. He says that the higher temperatures actually change the molecular composition and weakens the metal."
Pshaw. The temps aren't that much higher. Insulation as it is on my stuff mainly serves to prolong cool-downs thus reduce cold starts while not increasing running temps- according to coolant gauge- all good stuff.
"2) Running thinner lubrication. He says that thinner lubes essentially run like water, increasing friction. So this adds excessive heat, which due to thermal expansion increases friction again. All in all, greatly increases wear."
I wouldn't go thinner than the OEM recommends for winter ops, but I run that year-around.
"3) EOC. Wears out batteries, wears out starters, wears out cooling system, wears out engine."
I usually bump start plus I have less urban/commuter ops than the average bear (more highway) so it's possible I am easier on the battery and starter than the average motorist! Re: wears out cooling system and engine: I fail to see how. 