If this is your first oil change, it would be good to have it changed at your first convenience, but don't worry. These are robust trucks. I'm at 214,000 miles and have let two or three oil changes go into the negative percents. Once in the negative percents, the RL will chime at you at intervals to remind you. Probably anything that could go wrong with your engine will not be blamed on letting the oil change go a little past 0%.