T&T: Running engines during off-season

[Cole on Voyager]

What's you guys feelings on running your engines every once in while 
during periods of non-use?
The PO of my first boat, which had DD 6v-53's recommended running them 
until the oil warmed up once a weeek.
I tended to go more like 10 days to two weeks, and have continued that 
with my current boat and it's TAMD-60C Volvo's.
The Volvos seem to have a harder time getting warm without a load on 
them than the old Detroit's.

This time of year  I try to wait until we a get a warmer day, my engine 
room temperature has hovered in the mid-upper 30"s for the last two 
weeks and they don't like to start without a fair amount of cranking at 
those temperatures. I bought one of those thermometers with a probe 
designed to stick outside, but I have the probe in the engine room, that 
way I can watch the temperature there and in the salon ( I live aboard) 
at the same time.

Cole
m/v Voyager
1984 President 41