Warm it up as you drive. It gets zero miles to the gallon out there idling. The worst thing is to run it for a tenth of a mile and then shut it off. This invites condensation to form inside the engine. You might want to consider synthetic oil. I think one of its advantages is that it leaves a coating in the engine so that you eliminate the problem of running an engine for a couple of seconds with no oil upon start-up when cold has contracted the steel and reduced the tolerances. Other bricksters will know more about this than I do