I thought I read somewhere they set them for better emissions when warmed up. I'm not sure which tier brought the change. At 20 degrees I might have 2 or 3 seconds of popping but not bad enough to worry about.
Hhhmmmmm... If it is just to get a better start up in cold weather, I would leave it alone. That's what block heaters are for. He had a pretty nice garage, lots of places to plug in.
I may just leave it alone and plug it in next winter when I get some outlets wired. But on the other hand I have a hard time leaving well enough alone and like to tinker with things.