Time Warner Cable has begun replacing aging gasoline-fueled vans with diesel-powered Ford Transit vans that should improve fuel economy by nearly 50 percent, according to the company.

So far this year, the cable provider has added nearly 500 diesel Transit vans around the country as service vehicles for its installers with plans to add additional units later this year. The Transit vans are replacing a blend of Ford E-Series and General Motors' G-Series vans.

Time Warner Cable expects a 47-percent improvement in mpg with the move, according to Shelley Loo, a company spokeswoman.

"We specified this truck because of the high torque, high efficiency diesel engine," said Loo. "It's a central part of our strategy to purchase more efficient drive-lines."

Ford's 2014 E-150 cargo van achieved 16 mpg on the highway and 13 mpg in the city with a 4.6-liter V-8 engine.

The new vans are part of the company's "Go Green" initiative to by "raising environmental awareness, using fewer natural resources and generating less waste in our business," the company has said. One part of the initiative involves adding more fuel efficient vehicles.

So far, the company has reduced its carbon intensity by 38 percent over two years, which exceeded a goal set in 2012 of a 15-percent reduction. The company achieved a 14.7 percent increase in fuel efficiency from 2012 in its fleet by purchasing more fuel efficient vehicles, the company announced in March.

From 2013-2014, the company made Ford Fusion Hybrid the standard passenger car, which helped it achieve a 33-percent increase in fuel efficiency and saving a future estimate of 30,000 gallons of gasoline and 210 tons of carbon dioxide equivalent monthly.

At the same time, the company replaced 173 vans in New York City with new Transit Connect compact vans, which saved 553 gallons of fuel equating to $2,245 and 5.35 tons of carbon per month.

Time Warner Cable operates nearly 20,000 active vehicles in its fleet.