Pic related, Brazilian narrow gauge slug (M1).
>>2015280Yet the majority of heavy duty (non-marine) diesel makers and truck manufacturers have decided on SCR as the better solution.
Seems like it was the class I RRs encouraging manufacturers to go down that route for the reasons you mentioned. Funny thing is Tier 4 locomotives seem to be pretty slow sellers, having orders in the 100s and no company outside the US is buying them either.