I have a '97 SC2 with about 93,000 miles on it, and I've been religiously changing the oil every 3,000 miles, and up till now I've only used standard 10-30 in the summer, and 5-30 in the winter, per the owner's manual instructions. My question to the group is, does anyone have an opinion about the high-mileage oils, like valvoline's Maxlife or penzoil's high mileage oil? If I start shelling out the extra money, however much it is, for the fancier oils, like those, or a synthetic, am I likely to see a long-term pay off from it? Do they actually work like the wonder lubricants they claim, or are they not really worth it? Any advice would be much appreciated. thanks, joe