Taxi industry officials are calling dangerous Mayor Bloomberg’s plan to quickly replace Ford’s Crown Victoria vehicles with fuel-efficient hybrid cars.

Of the nine hybrid models approved by the Taxi and Limousine Commission, not one meets the safety, durability, and comfort standards of the industry’s most popular vehicle, the bulky, gas-guzzling Crown Victoria, the officials say.

The most frequently employed hybrid model on the street today, the Ford Escape, last year received a three-star rollover rating from a federal review agency, the National Highway Traffic Safety Administration. The Crown Victoria was awarded the maximum five stars, beating out all of the hybrid competitors that have been tested.

“I am truly fearful that the Ford Escape is not as safe as the Ford Crown Victoria,” the executive director of the Metropolitan Taxicab Board of Trade, Ronald Sherman, said. “It is not purpose-built for our industry and our tough streets, and I will not run them until I have to.”

Industry officials also said that without proper testing, drivers would be forced to purchase hybrid vehicles that could break down due to the constant use, forcing the industry to shoulder the higher repair costs associated with the hybrids.

As part of Mr. Bloomberg’s PlaNYC development and energy proposal, city officials announced last month that all vehicles retired after October 2008 must be replaced with hybrid cars that run at least 25 miles to the gallon.

Mr. Sherman said he wants the city to extend the deadline at least another year so hybrids could be tested on double 12-hour shifts and manufacturers could have the time to custom-build vehicles as safe as the Crown Victoria.

A spokesman for Mr. Bloomberg said many fleet owners are supportive of the city’s hybrid plan and that the city has taken measures to ensure that the models are safe for taxi use.

“Models were identified for use as taxis that meet the most rigorous safety standards, reduce operating costs, and meet the goal of improving our city’s air quality,” the spokesman, John Gallagher, said in a statement.

When Mr. Bloomberg in April announced plans to replace the city’s taxis with hybrid vehicles, his administration expressed some concern about whether hybrid cars could survive the wear and tear of constant use.

“These vehicles are in the first years of use and questions regarding their durability as 24-hour, seven day a week vehicles have yet to be fully answered,” the mayor’s report read.

A month later, Mr. Bloomberg appeared on NBC’s “Today Show” and, alongside a row of Ford Escapes, said the city would enforce the switchover to hybrid models starting in October.

The chairman of the City Council’s Transportation Committee, John Liu, said he is concerned that the city’s desire to quickly introduce more fuel-efficient taxis onto the streets has come at the expense of safety.

“There is some concern that perhaps the TLC has not fully considered the safety ramifications in their haste to make this decision,” Mr. Liu said. He said he is considering holding hearings on the safety standards of the hybrids.

Ford Escapes made their debut as city taxis in November 2005, as part of a pilot program sponsored by Council Member David Yassky of Brooklyn.

“I think it’s always difficult to change, but here’s where this industry has to change,” Mr. Yassky said. “The global warming problem is not going to change. The city’s asthma problem is not going to change. We don’t have time to wait.”

Beyond safety issues, industry officials have concerns about the comfort of the hybrids currently on the market.

The managing director of the League of Mutual Taxi Owners, Vincent Sapone, said hybrid vehicles are too small, which could lead to roomier, non-hybrid livery cabs luring away the taxi industry’s share of airport pickup. “These passengers won’t be able to fit back there,” Mr. Sapone said. “I think there’s going to be a lot of complaints, and it’s going to hurt the industry.”