You’ve got to be kiddin’. Clean is a relative term, and there is nothing “ordinary” about any diesel choice now sold in America. We have extremely technologically-advanced diesel engines here due to the strict, fuel-neutral, EPA emission compliance policies and the engineers’ response to these new policies.

Diesels have become squeaky clean as compared to just a few years ago.

The following illustrates my objection to the author’s conclusion about VW’s TDI used in the new Jetta being “no technological break through”:
(1)Volkswagen offers the only four-cylinder diesel in North America for light-duty applications that meet 50-state emission compliance and has offered this same power train, which no challengers since 2008. (2)Any diesel car in America today is a technological marvel, because, in just three short years, engineers had to cut PM by 80% and NOx by 95% , making any diesel sold in America 90% cleaner than the ones produced in 2006. (3) This clean up was done while not sacrificing fuel economy and dramatically improving driving dynamics and refinement. (4)This engine, along with the 6.7-liter Cummins are the only engines that meet these ridiculously-low levels of NOx without the need for diesel-exhaust fluid. (5)I think the fact that the TDI engine gets 40% better than the standard power train is better than “reasonable economy”. Today’s full-size pickup trucks top out at around 20 mpg, highway. Imagine if one manufacturer added a power train to its line up that gave consumers 40% better fuel economy and garnered 28 mpg, highway. Would the author call that “reasonable economy”? (6) The author maybe comparing the 42 mpg to some of the new product offerings out today, but this TDI engine has been sold since August 2008. No one except Prius had anything that could touch this fuel economy at the time. Although this new Jetta has new skin, this is not a new power train that can be compared to the new Cruze or the Eco-box choices that have recently arrived on the scene. Moreover, nothing comes close in performance to VW’s TDI in the over 40 club, with its 236 foot lbs of peak torque from 1750-2500 RPM. (6)Readers should note that any diesel can run on any blend of biodiesel without significantly impacting fuel economy while simultaneously drastically cutting down the use of petroleum, carbon lifecycle emissions, and many toxic exhaust fumes that are currently present in both gas and diesel cars using petroleum-based fuels. By comparison, if you want to use ethanol greater than 10% blend, you must find an E85 capable car and you should be ready to lose 24% fuel economy. If you opt for something like a CNG car be ready for lost fuel economy and suffer severely restricted range and limited car choices. You can choose between a Honda Civic and a Honda Civic. With diesels and biodiesel , it is a drop-in technology. The diesel is ready for the fuel the day you buy it with the user just taking a few precautions in cold weather as the only drawback.