Just did my initial oil change to Mobil 1. While under there, I noticed a message embossed on the oil pan - "Special oil drain procedures required, see shop manual", or words to that effect. Anyone know what those "special procedures" might be? I let the oil drain for about 1/2 hour, there was barely a drip when I replaced the plug. When I refilled however, it only took 6 quarts to reach the upper end of the "Full" range on the dipstick. Are the "special procedures" (whatever they might be) needed to get out that last 1/2 quart of old oil? I've been changing my own oil for years, haven't seen anything like this before.