My dart is at 7% on the olm. I've gone 7400 miles. My car takes 0w20 so assuming i stick with the viscosity recommended I guess that pretty much only leaves synthetics. That being said could I go to 10,000 miles ? Or should I not go past the olm. I've never gone over 5000 or so on an oil change but the oil even at 7400 miles doesn't look bad and I realize going longer on good quality oil is possible. So opinions please. Also in regards to synthetics seems like you can't mention synthetic without Mobil 1 coming to mind. Why is it a lot of people experience noiser engines with it and higher iron wear? Is that not a huge deal I guess? Any rhyme or reason to it?