In the grand scheme of automotive maintenance is oil really that important? As long as you change your oil in a reasonable time does it really matter what oil you use and what interval? Does it matter if you use the best Group 4 oil with the lowest NOACK and a Fram Ultra versus using any approved oil? Will I see real world benefits like engine running better after 100k miles? I was reading a few posts here and it seems like our cars are falling apart. Cars are rusting out, oil is leaking out of every gasket on the engine, rubber hoses all cracked, factory original suspension at 200k miles and 10 years, people exploding their timing belts, etc. Are we misplacing our time and effort in focusing on motor oils?