I don't make the 5K miles in the six-month interval, so I use the calendar instead of my odometer. I drive 95% city and a couple of road trips a year of over 2,000 miles round trip. That's why my second oil change was done a year after I bought it with just 8,800 miles. Now that my free ones are over, I also will be going full synthetic. I've done some research on types, viscosity, and prices. There are a lot of options, so the next six months will be spent deciding. The most important thing is taking care of that baby and being comfortable with that schedule. Keep me posted on the type of synthetic you choose. My service consultant at the dealership said I could bring my own and they would only charge for the filter and labor, so it won't cost much there. The cost is the lubricant.