Eco-friendly Ford Fusion hybrids are joining Nissan Altimas to replace sturdy, but fuel-consuming NYPD Chevy Impalas. (NYPD/Sipa)

It's NYPD green.

Cops introduced the first Ford Fusion hybrid patrol cars on Wednesday as the fleet slowly turns more eco-friendly.

"These vehicles use less fuel and emit fewer pollutants into the air we breathe," Mayor Bloomberg said.

The first 30 of 102 Fusions join 76 Nissan Altima hybrids that are gradually replacing 3,000 gas-guzzling Chevy Impalas that regularly prowl the streets.

The Ford Fusion gets an EPA-estimated 41 miles per gallon - more than double the gas mileage of the iconic Impala patrol car. The effort is part of a plan to reduce the city government's carbon footprint 30% by 2017.

"It's a bonus when we can add outstanding fuel economy to the mix," said NYPD Commissioner Raymond Kelly.