Mobile 1 5W30 changed every 3,500-4,000 miles here too. Alway change the filter at every oil change. I'm at 62k miles now with no oil consumption between changes. The cleaner you keep it, the longer it will last.

 

Ok, so far I've been changing my oil every 5000kms (~3000miles) using Mobil 1 & an AC Delco filter (Walmart sells them both at a good price) but since synthetic is supposed to be better than "regular" oil (for 3 X as much, I'd hope so ) it's supposed to last longer right?? But if I didn't follow the maintenance schedule that the owner's manual sets out, would the warranty be void if a problem ever occurred because I didn't change the oil as frequently, even though I was using synthetic??? This is totally hypothetical, cause I have been doing oil changes according to "the Book" so far, but for the cost of synthetic oil, if I could extend the time between changes without affecting the warranty, I'd certainly like to do that.

If anyone knows for sure, that would be great.