I know it has probably been discussed a million times, but when I tried to search, I came up empty.
98 Deville, 60K miles. It was serviced regulary by a dealer, but I don't know what type of oil they used. I would be willing to bet it wasn't synthetic, but don't know if it was 5W30, 10W30, 15W40, etc.
I also need to know if these engines require just an "API" rating or the API with energy conserving values such as Penzoil. I have always used Penzoil in my cars, but never had a N*
:thepan: More than a million times in these threads........read your owner's manual. FWIW, I use Pennzoil Platinum 5W-30 synthetic and WIX 51522 filters. Uses a quart every 3,500 miles. 60Kmi is nothing to a N*. Run the hell out of it.
Factory recommends 10W30 conventional. Whatever brand tickles your fancy. There have been more oil wars fought here than I care to remember. Search again. You MUST be doing something wrong. You should find so much to read that you will never finish it.