Since last 16k miles(i.e. the time i started keeping log), independent mechanic, i bring in oil and filter and give them to change. I am sticking with 15k mile interval for full drain and replace filter as per oil specification( Mobile 1 Fully Synthetic oil + Mobil 1 filter). Will be now switching to 10k miles or 1 year whichever happens earlier. I check regularly and top up if the oil is low.