synthetic oil when you and I can go to any store and buy synthetic oil for not that much more than conventional. If you DIY oil changes, you'd be an idiot to not use synthetic.


This is just a fact: Synthetic oil at 10K miles in is in better shape than conventional at 3K miles in, and it's not even close. They both start out about the same (they have to to have the same viscosity and temp rating). But conventional starts breaking down immediately while synthetic hangs tough for a long time.


I've also experienced synthetic cleaning up an engine and helping it run smoother. Bought a commuter car once with 100K miles on it. Within one oil change of synthetic the difference was significant.


I only use synthetic now. Just gives extra peace of mind.