'97 Aerostar, 163.5K miles.
Havoline 10W-40 (clearance at WM last year)
AAP Total Grip filter.
The heavy oil will no doubt kill fuel economy, but it should also make the engine blow up before this becomes a problem
Opel Omega 2.0 -88 399500km
4.5 liters Motox Superlite 5w-40 Full synthetic
Opel original filter
Valvoline engine flush
Also changed oil on my moms car, i poured in all the leftover oils from the storage shed and left the old filter on. The car will probably face the scrap yard due to several issues not worth fixing anymore.