Oil change every 5K miles or 3K???

dealership told me every 5k miles.

 

About a month or two ago I posted a Used Oil Analysis on my 2004 Prius, which had run slightly over 8,000km on Mobil 1 0W-30. The wear metals were remarkably low, zero moisture, zero fuel, etc.

About the only "concern" was a high Na reading. That has been resolved, look for it in a new post here.

At least in my case, after a few UOA, I'm entirely confident in Mobil 1 even in cold Winnipeg city driving. It's clearly capable of twice the recommended change interval, and I'm willing to do this and run another UOA.

Perhaps if you're running a No Name 5W-30 that barely meets the lame North American API specs, a shorter interval may be necessary. Without a UOA to verify this, I shudder to think of the environmental damage from all those oil changes, especially oil filters leaching in a landfill.

BTW: The Prius sold in the EU has a recommended oil change interval of 12 months or 16,000km.