Avoid sticker shock
It is important to have a sicker in the cab door jamb that indicates this vehicle complies with California and U.S. emissions as opposed to just U.S., if the vehicle will be registered in California. The engines are no different, regardless which state they operate. It is just much easier to register a vehicle in California with this identified on the vehicle.
If you are building a stock vehicle, it doesn’t hurt to chose California Registry so that the sticker denotes the vehicle meets regulations for that state. Only the label changes, so this provides a level of flexibility to the customer. Some OEs may provide the verbiage about California compliance as standard, be certain to verify.
The CARB sticker is for idling, do not confuse it with California Registry compliance. If your customer needs to idle more than 5 minutes, several states require a CARB compliance sticker on the side of the vehicle. It can be added after build but is a nuisance plus several hundred dollars. As with California Registry, nothing changes about the vehicle, its only an identifier.
See the link for regulations on emissions and how they drive today’s offerings.
The proposed standards would become 2.5% more stringent every year from model years 2021 to 2027. The proposed program would reduce CO2 emissions and fuel consumption for these vehicles by about 16% beyond Phase 1 when fully phased in.