Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed.
On the diesel Passat, the TDI badge stands for Turbocharged Direct Injection, which isn't really all that helpful as the gasoline-powered Passat is also turbocharged and also uses direct injection. Volkswagen attempts to clear this up by calling this Passat the Passat TDI Clean Diesel.
When the time came to get rid of / trade in my `97 Audi A4 1.9 Tdi 110 with 185k miles according to the newstand price guides mileage calculator it was worthless!. I got Â£2750 trade in for it though. I`m sure the dealer will sell it for a few bob more too and why not it still ran sweet even at those miles.