I don't think that is true. Why? I spent a career in automotive and the one recurring theme was always money, how can we shave a few more cents off this part and that part, it never ends.
It's common knowledge not to buy the first-year production of a new or redesigned model, the though is let them work the bugs out. Usually, those bugs are worked out within 180 days of production start. After the 180 days, they start with the cost savings and incorporate the cost savings into the following model years. Buy a new or redesigned model in the second half of the production year.
Late model diesel designs now process emissions in the exhaust, downstream from the engine. The engine is once again tuned for efficiency and performance. Yes, there is still an EGR (Cummins has eliminated it in new engines) but if you have a late model diesel, take a look at the EGR commanded values, very minimal.
If the automakers put reasonable resources into the exhaust treatment, like Cummins does for the OTR industry, there wouldn't be an issue like we see with the Cummins/RAM law suites while we hang in the balance.
