I agree with getting the casting/machining glop out early. I changed the factory fill and filter in my Hyundai V6 at 600 miles and refilled with SuperTech 5W-30 as a "light weight" break-in aid. (Hyundai recommends 10W-30 in my expected temperature range, and a max of 55 mph for the first 1,200 miles, but I second-guessed their engineers on the break-in oil weight to promote controlled wear.) I then drove until the odometer hit 3,000 miles and drained and replaced the 5W-30 with 10W-30 Chevron Supreme dino and filter. I've noticed no oil usage with the 5W-30 or the two subsequent refills and filter changes with 10W-30, so I suspect the rings are nicely seated. Would I have fared just as well if I'd followed the owner's manual to leave the factory fill oil in for 3,750 miles? Intellectually I'd have to confess, probably. But I like the emotional gratification I got from pro-actively involving myself with my engine's break-in. So, how soon will I switch to synthetic? When the netherworld freezes over.
[ October 15, 2003, 02:31 PM: Message edited by: Ray H ]