Basically every diesel engine after the early 2010s needed to have several emissions systems (EGR, DPF + DEF). You can do some reading on them if you're curious, but they basically all reduce reliability, efficiency (DPFs choke exhaust, and airflow is critical to a diesel running well), and power from the same engine without them.
In terms of legality, it means manufactures need to include all of those systems and their associated complexity, but the way that this startup is getting around it is using engines that were built before those requirements and are thus grandfathered into not needing them.
Also on the legal side, there's a thriving black market of mechanics who are willing to rip all those systems out of diesel engines. It's not uncommon to see double-digit percent increases in both power and fuel economy after it's done. The EPA has prosecuted a few cases against shops and parts suppliers for those "diesel deletes"
> Basically every diesel engine after the early 2010s needed to have several emissions systems (EGR, DPF + DEF)
Not true at all.
Every diesel engine sold after the early 2010s is not permitted to emit a certain amount of soot particles of certain sizes, and not permitted to emit certain concentrations of certain gases.
Manufacturers don’t have to use a DPF or EGR or DEF to achieve that. They can do it however they want.
Having lived around Africa for three years and in Latin America for two, I’m extremely happy the EPA doesn’t let vehicles belch black smoke into the air.
FWIW I’m a car nut, currently own a diesel with all those systems. Have also owned a 6BT 12 and 24 valve. I do not want to stand, or have my kid stand near the exhaust.