Smaller, more cost-efficient emergency fire vehicles are on the way.

As part of a pilot program, the Arlington Fire Department began sending a light response vehicle, rather than a fire engine, to respond to emergency medical calls. The trial, which began in March at Station No. 2 in east Arlington, showed potential for significant cost savings, Arlington Fire Lt. Darrel Whitfield said.

"This reduces wear and tear on our fire engines, and on our firefighters," Whitfield said. "There are tremendous benefits to taxpayers."

Emergency medical calls, such as difficulty breathing, chest pains or stomach aches, account for nearly two-thirds of calls the Fire Department receives. Light response vehicles — sport utility vehicles equipped with medical equipment — can answer most of those calls just as well as heftier fire engines, fire officials say.

Fire engines cost about $550,000 and are under warranty up to 120,000 miles. After that, the city is responsible for maintenance and repairs. Light response vehicles, which cost less than $50,000, would reduce the number of miles on the heavy fire engine by an estimated 12,000 each year and save about $11,500 each year in fuel costs. That would extend the warranty and life of engine for years.

"Arlington is such a busy city, and the fire engines get so much wear and tear on them," said J.B. Lopez, a firefighter who has frequently driven the light response vehicle. "This makes good sense."

Light response vehicles also improve safety, freeing up the large engines to respond to the most pressing fire emergencies, Fire Chief Don Crowson said.

The light response vehicle is used at Station No. 2, 1727 Sherry St., for the pilot because it is the busiest in the city, Whitfield said, responding to about 4,000 calls a year. An existing SUV was used for the pilot program, he said, and no additional staff was hired to man the vehicle.

Next, the department will test the concept in the northwest section of the city, where Station No. 4 covers a large number of nursing homes and assisted-living centers, Whitfield said. After that, Station No. 9, which includes the Parks at Arlington Mall and busy highways, will see a light response vehicle.

"We are stewards of the public's trust and funds," Crowson said. "We will always be there for emergencies, but we need to be as efficient as possible in doing so."