My last change was in April, just checked it 2 days ago - still clean, not burnt and full. I've used regular conventional oil in my '02 Dodge since I've owned it (2nd owner/bought in '04). I didn't drive much over the summer ( biked to work ) and even recently I haven't driven much. Used to waste money on changing the oil every 4 months (never drove 4000 miles before 4months) like the MFR recommended, now I just check it every now and then, top off when low, and change when filthy. I only drive around 2000-3000 miles a year.