The City of Houston expects to save about $110,000 a year in fuel and maintenance costs by issuing 27 Nissan Leaf electric vehicles to city workers as part of a broader sustainability initiative that also includes car sharing.

Each Nissan Leaf costs $473.98 per year to fuel while gasoline-fueled Nissan Rogue SUVs in the fleet cost $1,925.25 a year to fuel, reports EV Obsession.

The city has been adding electric vehicles to its fleet of 9,277 cars, vans, and trucks to reduce cost and greenhouse gas emissions as well as "promote sustainable transportation options for residents and visitors," according to a report by the Electrification Coalition.

The city expects a more than 600,000-resident population increase by 2030, growth that has created air quality issues that have become increasingly difficult to manage.

The city plans to add even more EVs to its fleet in the coming years, said Laura Spanjian, the city's director of sustainability.

In 2010, the city converted 15 Toyota Prius hybrids to plug-in hybrid vehicles. A year later, the city was among the first to get the all-electric Leaf. In 2012, Houston and Austin were among the first cities to get the Ford Focus electric vehicle.

In August of 2012, the city launched a car-sharing program for its employees called FleetShare in a partnership wih ZipCar.