The old Touareg with a V10 TDI was a bad buy as the 5.0L V10 wasn't good on fuel, but the TDI after 2011 with the 3.0L V6 TDI with the 8 speed is a great SUV with lots of torque for hauling. MPG should be better than 30mpg. Remember, it's a SUV not a monocoque fwd car. Check out used ones on autotrader and save around 15,000$-20,000 compared to new ones. Many 2011s are in the 30,000$ range. Most heavy SUVs will get around 14-25 mpg with gas engines. If you want a luxury SUV with lots of torque and pass the 30mpg range, then the Touareg TDI is the only thing on the American market as of 2013. In 2014 jeep in conjuction with fiat plan on offering a 3.0L V6 TDI from Fiat with an 8 speed auto. Mazda will offer the CX-5 with a 2.2L SkyactivDiesel that gets around 40mpg.
I think VW will have to offer the TDI in the Tiguan to compete with Mazda in 2014.