You’ve probably seen this PZEV logo on different cars, but what does it mean? It stands for Partial Zero-Emissions Vehicles. This means that vehicles with this logo meets the emissions limits for a Zero-Emissions Vehicle (ZEV).
Source: Rock River Times
These type of vehicles are easier to make as well. Creating pure EV versions, or hybrid versions of a car needs a lot of changes in the car’s design. However, creating a non-hybrid PZEV is easier, they have the same engines and are built on the same platforms.
A PZEV has three unique components in its fuel system and one in its exhaust.
Source: LA Car Guy
Anti-Permeation Fuel System Liners
Engineers that build PZEVs line the insides of fuel caps, fuel hoses, seals, gaskets, and plastic fuel tanks with layers of ethylene vinyl alcohol, or other low-permeability polymers, to keep fuel from soaking through. This will prevent off-gassing as the vehicle is not being used.
Carbon Canister Scrubbers
Temperature changes can cause gasoline to evaporate into the atmosphere. So to be able to capture gas even before it reaches the air, a canister of activated carbon is installed in the fuel-filling line from cap to gas tank.
Source: Alfa img
Carbon Air Intake Trap
When an engine is shut off, the fuel vapour stays in the combustion chamber and intake manifold. It will evaporate, so a filter of activated carbon will grab these outgoing hydrocarbons before they escape into our atmosphere.
Close-Coupled Catalytic Converters
These convert pollution gases into less harmful gases. Therefore, PZEVs can help reduce emissions that lead to pollution problems.