Bruce in Alaska wrote:

If you knew ANYthing about modern Diesel Engineering, you would KNOW,
that diesels get up to "Operating Tempratures" at loads of between
5 and 10%, and then the Cooling System dumps the rest of the BTU's

Heat rejection to the cooling system isn't representative of localized
temperatures and a host of other factors in the combustion chamber that
cause problems at light loads. These problems are not all that serious but
they do somewhat offset the wear and tear benifits of running and engine too
lightly for very long periods.

Your properly sized diesel or generator is not likely to suffer from any
amount of light running that is dictated by operating conditions. However,
if it is significantly too large for the job so that it NEVER comes up into
it's intended operating range, you probably won't get more, and quite
possibly, less, service out of it than if was run normally.

--
Roger Long