Cummins 6.7L Propane engine no EGR but meets emissions

https://www.trucknews.com/equipment...with-diesel-like-performance/1003141339/

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Saradhi Rengarajan, technical project leader with Cummins, said the most exciting aspect of the project was the torque the designers were able to achieve. Peak torque is 900 lb.-ft., far exceeding propane engines already in the market.

The efficiency of the engine has also led to favorable emissions performance, with CO2 emissions 11% less than a diesel, Rengarajan noted, while traditionally LPG engines had greater CO2 output than diesels. He said the 6.7L LPG offers a 28% improvement in CO2 output compared to propane engines in the market today.

Part of that CO2 improvement came from optimization of the combustion system, which allowed Cummins to avoid exhaust gas recirculation (EGR). The biggest challenge designers had to overcome when testing the engine was related to injector failures, which caused the company to adopt a vapour phase injection (VPI) system, sacrificing up to 1% in thermal efficiency in exchange for greater reliability.

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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

The EGR modules with liquid cooling have been maintenance “nightmares” on SOME industrial diesel engines.

Educate me, I do not know of late model industrial diesel engines using only VVT for emissions-passing certification.

We had a past thread here about Ford’s new HD gasoline V8 engine for HD pickups and Midline transport and offhand I cannot remember the NOx equipment it had.(I still have not seen a “convoy style” fuel economy test of that engine)

I would have to re-search but my fuzzy memory is that perhaps some Industrial CNG or LNG Engines can meet today’s USA emissions for NOx without cooled EGR.

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.