etruck.com.au

This video shows a Navistar engineer demonstrating their latest engine offering, the 13 litre Maxxforce built to comply with the extremely tough US EPA 2010 exhaust emission regulations.

Based on the 13 litre MAN engine, the new power plant has to use every trick in the book to keep the emissions down low enough to meet the criteria. There are two turbos each of which are connected to a different cooling radiator to get the recirculated gases down to the right temperature for reintroduction into the air intake.

Altogether there are four radiators as well as the air conditioning system using the air coming into through the front grille to reduce temperature. The air management system looks extemely complex and the engine compartment looks full of add-ons needed to control combustion and the production of illegal emissions.

I am no engineer but this engine looks like it was designed around one concept, to avoid using SCR to control emissions. It looks like the International marketing department have decided the best way to sell trucks is to not use the technology every other truck maker has chosen, SCR, and then bag the system as a marketing strategy.

The decision to head down the absolutely-no-SCR path seems to have forced the Navistar engineers to throw every single thing in the toy box at the engine’s systems in order to keep particulates and nitrogen oxides below the new limits.