Cleaner diesel is here

Just wanted to make a man-on-the-street report that I had my first encounter with ultra-low sulfur diesel this week, filling up my TDI's tank on a road trip to Santa Fe. As I noted before, this only means about 10% cleaner emissions for us current diesels, but newer diesels will be able to reduce emissions 90-some percent.

I did hear that current diesels could be retrofitted to have the same reduction. If anyone knows the specifics of retrofitting a VW, let me know!