The New Haven Fire Department is one engine down.

The city’s fire chiefs faced tough questions and a largely skeptical public at a Public Safety Committee Wednesday night for their decision to retire the engine — one of 12 in New Haven. The fire officials discussed their March decision to retire a fire engine this August in exchange for two Advanced Life Support vehicles. But committee members, firefighters and New Haven residents voiced their concerns that the decision, which was not discussed with the public beforehand, will increase some response times for fire emergencies. The audience added that the decision will result in minor savings, but was not budget-related.

Fire Chief Michael Grant said the decision was a response to an increased need for medical service, and a decreased need for fire response.

“My decision was based on life safety for the city of New Haven, not costs,” Grant said.

The decision would retire Engine 8, one of two engines at the station on Whitney Avenue. The vehicles that will replace the engine will provide emergency medical service.

Since 2001, Assistant Chief Patrick Egan said, the department has seen a 20 percent decrease in overall emergency calls into its stationsand a 50 percent reduction in calls for structure fires. Meanwhile, officials said that each of the department’s advanced life support vehicles handle 6,000 to 6,500 calls annually for medical service, which has resulted in increased response times, missed calls and staff fatigue in the past.

Primary response times for fires would stay the same throughout the city, but Egan said that secondary response times would increase depending on each station, but that they would still remain below the national four-minute response standard.

During the time for questions, community members said they did not understand why the decision to retire engine 8 justified the increase in response times. Ray Saracco, a city firefighter, told the committee that in addition to the predicted total predicted response time, it takes one minute to receive the 911 call, and two more minutes to get out the door.

“[The predicted response time] is virtually impossible unless you have a spaceship,” Saracco said to applause from the audience. Saracco said he supported the ALS service that would be improved by the exchange, but disagreed with the removal of a fire engine to support it.

Although Grant said the decision is no way budget-related, the move will result in a savings of about $70,000 to $80,000 from removing four firefighters manning the engine and adding four paramedics to staff the vehicles. But savings will also come from an increase in billing to those who receive treatment from the new vehicles. Egan said he could not confirm what that additional income could be, because it would not be managed by an external billing service.

Grant told the committee he did not consult the public in his decision, but he did not mean to alienate them.

“It was not my intention to exclude people,” Grant said. “If I could do it again I would.”

When Public Safety Chair Alexander Rhodeen asked how many people in the audience would like Engine 8 to stay, all members of the 70-strong crowd raised their hands.

“I think this decision was a disservice to the neighborhood, and a disservice to the chiefs,” Rhodeen said at the meeting’s close.

The department will add seven additional paramedics by the time the plan will be implemented in August.