I have a 2010 Dodge Grand Caravan 3.6L Flex Fuel with 208000 miles on it. What would be the recommended oil to use in it with this high of mileage?. I have been using the 0-20 conventional oil as marked on oil cap since I have owned it. Now I am thinking since it may be burning a small amount of oil because every week I have to add a quart. No drips anywhere. Should I increase the weight of the oil and go synthetic? I live in the desert so the engine operates in hot or warm weather all year.