ltra-Low-Emission Vehicles (ULEVs) reduce pollution emissions to the
lowest level possible for engines that burn fossil fuel. The most advanced
cars use compressed natural gas (CNG), engines built for higher compression
combined with sealed fuel systems that eliminate evaporative pollution,
two catalytic converters, and large fuel tanks for a normal driving range.
And the exhaust emissions are cleaner than the air in some cities--so
low they're nearly immeasurable.
ltra-Low-Emission Vehicles (ULEVs) reduce pollution emissions to the
lowest level possible for engines that burn fossil fuel. The most advanced
cars use compressed natural gas (CNG), engines built for higher compression
combined with sealed fuel systems that eliminate evaporative pollution,
two catalytic converters, and large fuel tanks for a normal driving range.
And the exhaust emissions are cleaner than the air in some cities--so
low they're nearly immeasurable. 
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