The 170hp TDI engine isn't certified for North American emissions. I'm hoping that will change with the NMS, the North American Passat replacement, with a 170 hp TDI engine but I doubt it. They could use this basic engine in the Audi A4 TDI, a Golf GTD, and other models. The V6 TDI engine has lots of power, is a blast, is the right choice for the Touareg and Q7 TDI. But IMHO, the right choice for any upcoming Audi A4 TDI is the 4 cylinder due to price and fuel economy. BMW's mistake was to only have a V6 diesel and not their 4 cylinder diesels in North American 335d. They didn't sell very well.
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