Ok lets think about this a minute. Where is wear occuring on cold start up? Is it the rods and mains?, cam bearings?, other valvetrain bits?,piston skirts?,cylinder bores?, rings?, all of the above?,some of the above?,or maybe even things that I left out.
I have read several cases where a stuck open thermostat resulted in excessive bore, piston skirt, and ring wear,and compariatively litte wear elsewhere. I remember reading a GM engineering study where they got several hundred percent more wear in these areas by leaving the thermostat out of an otherwise normal engine.
Ok if this is true then what is the wear mechanism? Is it rocking motion of the piston allowed by the extra clearances in a cold engine? Is the extra wear induced by combustion by products which are normally expelled in a hot engine and condense on the cylinder walls and combustion chamber due to lack of enough heat to "boil" them off. I understand that some of the combustion by products are acidic in nature and include nitric acid.
My hypothesis is that the wear is a combination of mechanical wear caused by cold clearances and erosive chemical wear induced by combustion by products and the lack of heat to drive them off the affected parts.
Aside from the power consumed a block heater makes a lot of sense to me.
Rickey.
