This question probably has been asked before, but I did a quick search and did not get a hit within this forum. I have a 2013 V6 coupe that rarely gets more than 4K or so miles on it during the year. In fact, as of this past weekend I have only put a little over 3800 miles on it this year. Also, I usually store it in whatever enclosed facility has the best cost offering at the beginning of November through the following April, with occasional running and driving it based on weather/road conditions. My question is what actually dictates when an oil change is required - miles driven or time since last oil change? I have always used Mobil 1 Full Synthetic and change the oil once a year whether I have reached 5K miles or not, and not based on the recommended date. Two other related questions - 1) based on my scenario if one oil change a year is sufficient should I do it before or after I store it for 5 to 6 months? 2) If my past oil change process is just plain wrong/stupid and might cause engine issues, should I get a thorough engine flush/cleaning performed to remove any excess sludge before the next new oil change. As always, thanks for the feedback and knowledge I gain from more experienced Mustang owners.