The automatic I have is EPA rated 29/40. The EPA admits their method for determining mpg, for diesels in particular, is way off. VW paid AMCI to independently come up with mpg figures, and they say 38/44. There are posts of people getting 50 or so. Since these things have barely hit the road, I'd say we've got a ways to go before we have reliable multi-tank mpg figures. Considering the fuel tank is 14.5 gallons, you could go 600 miles between refuelings. The dealer asked me to report my actual mpg back to them.
These will be in short supply until the US factory opens in 2010.
Yes, diesel is now more expensive than gasoline. Odd, that, since diesel is actually cheaper to refine. High demand for diesel, kerosene and home heating oil- all very similar products. Diesel prices are a lot less at Interstate truck stops than in urban centers. Diesels are about 30% more fuel efficient than gassers. Half that is because diesel has more energy (BTUs), half due to the inherent greater efficiency of a compression ignition system over a spark ignition system.
When you consider fuel efficiency, less maintenance (but what maintenance there is may be more expensive), and the longer lifetime of diesel vehicles (hence, higher resale value), I believe you come out ahead. The price difference for the diesel over the gasser version is officially around $2,000. Of course, some dealers, including the one I bought from, are jacking up the- er, uh, I mean, adding a market adjustment.