Not sure I understand the post. LOTS of late model engines don't have EGR anymore. VVT has helped eliminate the need. We now try to lower C02 emissions while equipping everything with catalytic converters that turn CO and HC into CO2 and H2O
Are you talking about gasoline engines?
I wonder if this would apply to CNG as well as propane? CNG stations for vehicles were pretty common in Oklahoma but not as much now it seems. Almost non-existent in some states. I guess propane is not that hard to find but perhaps not as easy after hours and usually not on the interstate.
So it sounds like this would be for stationary engines or vehicles that could stay close to refueling, ether public or private.
