In the industry I'm in, amongst other things, we install and maintain large pumps. Typically any where from 500-3000 gpm. These pumps are typically driven by an electric or diesel engine. The diesel engines are required by code to be installed either with a block heater OR be in an environment where the engine temp is always warm so it can start quickly and with minimal strain. These engines are required to be started weekly (manually or automatically) and run for 30 minutes minimum. This gives the engine ample time to get up to running temperature, lubricate sufficiently, and burn off any moisture accumulated internally during the first few minutes after start up. Pretty consistent with the heart of this thread I'd say.