Mobil 1 synthetic:
Mobil 1 comes in several different grades. Porsche is initially filling the Boxster with 5W-40, but this grade is not available in the U.S. In the U.S., Mobil 1 comes in four grades: 0W-30, 5W-30, 10W-30, and 15W-50. Porsche does not recommend the 0W-30 weight for any driving conditions. For the other three weights, you should pick a weight based on the following criteria:
* 5W-30 For areas where continuous ambient temperatures get below 32�F/0�C for significant periods of time.
* 10W-30 For areas where continuous ambient temperatures get below 50�F/10�C for significant periods of time but remain above 32�F/10�C most of the time.
* 15W-50 For areas where continuous ambient temperatures stay above 50�F/10�C most of the time.
Because of the long intervals between oil changes, you should probably pick the oil for the coldest temperatures the car will experience between oil changes. In climates with extreme weather changes, you might consider changing the oil twice a year.
Dealers have been charging in the vicinity of $120 for an oil change, including oil, filter, filter ring, and labor. You can change it yourself for less.