ULEV

Super Ultra Low Emission Vehicle (SULEV) is a conventionally powered or gas-electric hybrid vehicle designed to produce minimal air pollution at their point of use, typically less than 10% of that of an equivalent ordinary vehicle.
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A ULEV or Ultra-Low Emissions Vehicle is a vehicle that has been verified by the California Air Resources Board to emit 50% less polluting emissions than the average for new cars released in that model year. The ULEV is one of a number of designations given by the CARB to signify the level of emissions that car-buyers can expect their new vehicle to produce and forms part of a whole range of designations, listed here in order of decreasing emissions: TLEV: Transitional Low Emission Vehicle. This is the least stringent emissions standard in California. TLEVs are phased out as of 2004.
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Ultra Low Emission Vehicles[California]Better than LEV