The US government statistics on average fuel prices for February show that ULSD diesel is about 10 cents more expensive than unleaded regular gasoline. The highest prices are in New England, where lots of buildings use fuel oil to heat buildings.
Autoblog Green tested an Audi A3 Avant TDI (station wagon to you and me).
http://green.autoblog.com/2009/05/21/review-2010-audi-a3-tdi-diesel-with-a-healthy-dash-of-sport/
The article is generally positive. They achieved 34 mpg in a mix of urban and high speed backroad driving, in a vehicle equipped with a 2.0L 4 cylinder turbodiesel and paddle shifting automatic transmission. Downside is the price, which is around $30K, or about $6K more than a VW Jetta wagon with diesel.
Audi and VW sell their SUVs (A7 and Touareg2) with a 3.0L turbo diesel, rated for almost 400 ft-lbs of torque. VW has refreshed the Touareg for 2011, reducing weight by 450 lbs and making the vehicle a little more aerodynamic. EPA estimated highway mpg jumps from 25 mpg in 2010 to 31 mpg in the new 2011 model.
In other diesel news, Dodge RAM pickups powered by the Cummins 6.7L diesel engine meet 2010 emissions standards without using diesel exhaust fluid (DEF, the urea solution that helps catalyze oxides of nitrogen). However, the cab and chassis RAM models do require DEF. The DEF is an extra expense, but the DEF-equipped models are expected to return better mpg. So the running expenses may be the same.
2011 will see changes in other HD pickups. Chevrolet will have a revised 6.6L diesel, and Ford will introduce its new 6.7 'Scorpion' diesel and new transmission. Both will use DEF to meet the ever-tightening emissions rules.
Mahindra and Mahindra's diesel pickup introduction has been pushed back AGAIN to mid-Spring. There are rumors that M&M is talking with Navistar about using the big-rig maker's facilities to assemble pickups from knock-down kits shipped from India. The reason to do so is the 25% "chicken tax" that would be imposed on imported vehicles. Mercedes ships the Sprinter to USA as a kit for this reason as well.