Mr.Mark, The heat grid is in the intake to help when starting. It heats the incoming air.
Holstein13, There is a difference between "operating temperature" and "safe to operate". You can start moving as soon as you have safe oil pressure as long as you don't use wide open throttle. So if you have a ways to go getting out of the campground and to the freeway you can start moving. Your engine will warm up faster. If you have a very short distance to where you will need full power like entering a freeway I would let it warm up some before moving. If you don't want to sit and bother your neighbors you can move toward the exit. I like to do a last check before leaving the campground and I haven't found any place where there isn't room by the exit to stop and do this. This gives your engine a little more time (at fast idle) to warm up.
Bill
