Go for it. Delvac 1, which is the diesel version of Mobil 1 is one of the best oils you will find for use in a diesel vehicle. It has an API rating of CH-4 and is great at controlling soot. You should be able to double your change intervals and the synthetic will also give you the added benefit of helping your turbo run cooler.

The Delvac 1 only comes in 5W40, but that is not all bad because you can run in it in warm and cold climates as well. I think you would be very pleased by changing over to the synthetic, especially if you plan on keeping your car for an extended period of time. If you do change over I would highly recommend at least changing your filter at 1500 miles, if not both filter and oil. The synthetic will help clean out some of the gunk in your engine and the filter will get loaded up fairly quickly. Johnny